Alkylated cyclodextrin compositions and processes for preparing and using the same

ABSTRACT

The present invention related to low-chloride alkylated cyclodextrin compositions, along with processes for preparing and using the same. The processes of the present invention provide alkylated cyclodextrins with low levels of drug-degrading agents and chloride.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/604,504, filed, Feb. 28, 2012, which is incorporated by referenceherein in its entirety, including any drawings.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to compositions comprising low-chloridealkylated cyclodextrin compositions, and processes for preparing andusing the same.

2. Background of the Invention

Hydrophobic, hydrophilic, polymerized, ionized, non-ionized and manyother derivatives of cyclodextrins have been developed, and their use invarious industries has been established. Generally, cyclodextrinderivatization proceeds via reactions in which —OH groups at the 2-, 3-,and/or 6-position of the amylose rings of a cyclodextrin are replacedwith substituent groups. Substituents include neutral, anionic and/orcationic functional groups.

Known cyclodextrin derivatives such as alkylated cyclodextrins include,but are not limited to, sulfoalkyl ether cyclodextrins, alkyl ethercyclodextrins (e.g., methyl, ethyl and propyl ether cyclodextrins),hydroxyalkyl cyclodextrins, thioalkyl ether cyclodextrins, carboxylatedcyclodextrins (e.g., succinyl-β-cyclodextrin, and the like), sulfatedcyclodextrins, and the like. Alkylated cyclodextrins having more thanone type of functional group are also known, such as sulfoalkylether-alkyl ether-cyclodextrins (see, e.g., WO 2005/042584 and US2009/0012042, each of which is hereby incorporated by reference in itsentirety). In particular, alkylated cyclodextrins having 2-hydroxypropylgroups and/or sulfoalkyl ether groups have found use in pharmaceuticalformulations.

A sulfobutyl ether derivative of β-cyclodextrin (“SBE-β-CD”) has beencommercialized by CyDex Pharmaceuticals, Inc. as CAPTISOL® and ADVASEP®.The anionic sulfobutyl ether substituent improves the aqueous solubilityand safety of the parent β-cyclodextrin, which can reversibly formcomplexes with active pharmaceutical agents, thereby increasing thesolubility of active pharmaceutical agents and, in some cases, increasethe stability of active pharmaceutical agents in aqueous solution.CAPTISOL® has a chemical structure according to Formula X:

where R is (—H)_(21-n) or ((—CH₂)₄—SO₃ ⁻Na⁺)_(n), and n is 6 to 7.1.

Sulfoalkyl ether derivatized cyclodextrins (such as CAPTISOL®) areprepared using batch methods as described in, e.g., U.S. Pat. Nos.5,134,127, 5,376,645 and 6,153,746, each of which is hereby incorporatedby reference in its entirety.

Sulfoalkyl ether cyclodextrins and other derivatized cyclodextrins canalso be prepared according to the methods described in the followingpatents and published patent applications: U.S. Pat. No. 3,426,011, U.S.Pat. No. 3,453,257, U.S. Pat. No. 3,453,259, U.S. Pat. No. 3,459,731,U.S. Pat. No. 4,638,058, U.S. Pat. No. 4,727,06, U.S. Pat. No.5,019,562, U.S. Pat. No. 5,173,481, U.S. Pat. No. 5,183,809, U.S. Pat.No. 5,241,059, U.S. Pat. No. 5,536,826, U.S. Pat. No. 5,594,125, U.S.Pat. No. 5,658,894, U.S. Pat. No. 5,710,268, U.S. Pat. No. 5,756,484,U.S. Pat. No. 5,760,015, U.S. Pat. No. 5,846,954, U.S. Pat. No.6,407,079, U.S. Pat. No. 7,625,878, U.S. Pat. No. 7,629,331, U.S. Pat.No. 7,635,773, US2009/0012042, JP 05001102, and WO 01/40316, as well asin the following non-patent publications: Lammers et al., Recl. Tray.Chim. Pays-Bas 91:733 (1972); Staerke 23:167 (1971), Adam et al., J.Med. Chem. 45:1806 (2002), Qu et al., J. Inclusion Phenom. MacrocyclicChem. 43:213 (2002), Tarver et al., Bioorg. Med. Chem. 10:1819 (2002),Fromming et al., Cyclodextrins in Pharmacy (Kluwer Academic Publishing,Dordrecht, 1994), Modified Cyclodextrins: Scaffolds and Templates forSupramolecular Chemistry (C. J. Easton et al. eds., Imperial CollegePress, London, UK, 1999), New Trends in Cyclodextrins and Derivatives(Dominique Duchene ed., Editions de Sante, Paris, FR, 1991),Comprehensive Supramolecular Chemistry 3 (Elsevier Science Inc.,Tarrytown, N.Y.), the entire disclosures of which are herebyincorporated by reference.

Impurities present in an alkylated cyclodextrin composition can reducethe shelf-life and potency of an active agent composition. Impuritiescan be removed from an alkylated cyclodextrin composition by exposure to(e.g., mixing with) activated carbon. The treatment ofcyclodextrin-containing aqueous solutions and suspensions with activatedcarbon is known. See, e.g., U.S. Pat. Nos. 4,738,923, 5,393,880, and5,569,756. However, there is a continued need for alkylated cyclodextrincompositions with higher purity.

BRIEF SUMMARY OF THE INVENTION

The present invention provides a process for preparing an alkylatedcyclodextrin composition comprising an alkylated cyclodextrin, theprocess comprising: (a) mixing a cyclodextrin with an alkylating agentto form a reaction milieu comprising an alkylated cyclodextrin, one ormore unwanted components, and one or more drug-degrading impurities; (b)conducting one or more separations to remove the one or more unwantedcomponents from the reaction milieu to form a partially purifiedsolution comprising the alkylated cyclodextrin and the one or moredrug-degrading impurities, wherein the one or more separations areultrafiltration, diafiltration, centrifugation, extraction, solventprecipitation, or dialysis; and (c) treating the partially purifiedsolution with a phosphate-free activated carbon having a residualconductivity of 10 μS or less and producing the alkylated cyclodextrin.

In some embodiments, the alkylated cyclodextrin composition furthercomprises less than 500 ppm of a phosphate. In some embodiments, thealkylated cyclodextrin composition further comprises less than 125 ppmof a phosphate.

In some embodiments, the residual conductivity of the phosphate-freeactivated carbon is 9 μS or less. In some embodiments, the residualconductivity of the phosphate-free activated carbon is 8 μS or less.

In some embodiments, the alkylated cyclodextrin composition furthercomprises less than 0.5% (w/w) of a chloride. In some embodiments, thealkylated cyclodextrin composition further comprises less than 0.1%(w/w) of a chloride. In some embodiments, the alkylated cyclodextrincomposition further comprises less than 0.05% (w/w) of a chloride.

In some embodiments, the alkylated cyclodextrin composition has anaverage degree of substitution of 2 to 9. In some embodiments, thealkylated cyclodextrin composition has an average degree of substitutionof 4.5 to 7.5. In some embodiments, the alkylated cyclodextrincomposition has an average degree of substitution of 6 to 7.5.

In some embodiments, the alkylated cyclodextrin composition has anabsorption of less than 1 A.U., as determined by UV/visspectrophotometry at a wavelength of 245 nm to 270 nm for an aqueoussolution containing 300 mg of the alkylated cyclodextrin composition permL of solution in a cell having a 1 cm path length. In some embodiments,said absorption of less than 1 A.U. is due to a drug degrading agent.

In some embodiments, the alkylated cyclodextrin composition has anabsorption of less than 0.5 A.U., as determined by UV/visspectrophotometry at a wavelength of 245 nm to 270 nm for an aqueoussolution containing 300 mg of the alkylated cyclodextrin composition permL of solution in a cell having a 1 cm path length. In some embodiments,said absorption of less than 0.5 A.U. is due to a drug degrading agent.

In some embodiments, the absorption is determined by UV/visspectrophotometry at a wavelength of 245 nm to 270 nm for an aqueoussolution containing 500 mg of the SAE-CD composition per mL of solutionin a cell having a 1 cm path length.

In some embodiments, the alkylated cyclodextrin composition has anabsorption of less than 1 A.U., as determined by UV/visspectrophotometry at a wavelength of 320 nm to 350 nm for an aqueoussolution containing 300 mg of the alkylated cyclodextrin composition permL of solution in a cell having a 1 cm path length. In some embodiments,said absorption of less than 1 A.U. is due to a color forming agent.

In some embodiments, the alkylated cyclodextrin composition has anabsorption of less than 0.5 A.U., as determined by UV/visspectrophotometry at a wavelength of 320 nm to 350 nm for an aqueoussolution containing 300 mg of the alkylated cyclodextrin composition permL of solution in a cell having a 1 cm path length. In some embodiments,said absorption of less than 0.5 A.U. is due to a color forming agent.

In some embodiments, the absorption is determined by UV/visspectrophotometry at a wavelength of 320 nm to 350 nm for an aqueoussolution containing 500 mg of the alkylated cyclodextrin composition permL of solution in a cell having a 1 cm path length.

In some embodiments, the phosphate-free activated carbon is washed witha solvent until the eluted solvent has reached the residual conductivityin (c). In some embodiments, the phosphate-free activated carbon iswashed with water until the eluted water has reached the residualconductivity in (c).

In some embodiments, the alkylated cyclodextrin is a sulfoalkyl ethercyclodextrin of Formula (II):

wherein p is 4, 5, or 6, and R₁ is independently selected at eachoccurrence from —OH or —O—(C₂-C₆ alkylene)-SO₃ ⁻-T, wherein T isindependently selected at each occurrence from pharmaceuticallyacceptable cations, provided that at least one R₁ is —OH and at leastone R₁ is O—(C₂-C₆ alkylene)-SO₃ ⁻-T. In some embodiments, R₁ isindependently selected at each occurrence from —OH or —O—(C₄alkylene)-SO₃ ⁻-T, and -T is Na⁺ at each occurrence.

In some embodiments, the alkylated cyclodextrin composition is combinedwith one or more excipients.

In some embodiments, the alkylated cyclodextrin composition is combinedwith an active agent.

The present invention is also directed to products prepared by theprocesses described herein.

Further embodiments, features, and advantages of the present inventions,as well as the composition, structure, and operation of variousembodiments of the present invention, are described in detail below withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated herein and form a partof the specification, illustrate one or more embodiments of the presentinvention and, together with the description, further serve to explainthe principles of the invention and to enable a person skilled in thepertinent art to make and use the invention. The following drawings aregiven by way of illustration only, and thus are not intended to limitthe scope of the present invention.

FIG. 1 provides a graphic representation of a UV/vis scan (190 nm to 400nm) of solutions containing a SAE-CD composition after a single carbontreatment, in which the sulfoalkyl ether cyclodextrin concentration isvaried from 1% to 60% by weight.

FIG. 2 provides a graphic representation of a UV/vis scan (190 nm to 400nm) of solutions containing a SAE-CD composition after a second carbontreatment, in which the sulfoalkyl ether cyclodextrin concentration isvaried from 1% to 60% by weight.

FIG. 3 provides a graphic representation of a UV/vis scan (190 nm to 400nm) of a SBE_(6.6)-β-CD solution after thermal and caustic degradationat a temperature of 60° C. for a period of 0, 24, 72, 96, and 168 hoursto demonstrate degradation of β-cyclodextrin and formation ofdrug-degrading impurities having an absorption at a wavelength of 245 nmto 270 nm and/or color-forming agents having an absorption at awavelength of 320 nm to 350 nm.

FIG. 4 provides a graphic representation of a UV scan (190 nm to 400 nm)of a solution containing a SAE-β-CD after exposure to a temperature of70° C. for a period of 48 hours, with subsequent treatment with varyingamounts of activated carbon.

FIG. 5 provides a graphic representation of the effect of initial UV/Visabsorption of a SBE_(6.6)-β-CD solution on API stability.

FIG. 6 provides a graphic representation of the impurity levels by aprocess for preparing SBE_(6.6)-β-CD wherein the impurities are measuredusing a charged aerosol detector.

FIG. 7 provides a graphic representation of chloride concentrationlevels by a process of preparing SBE_(6.6)-β-CD wherein the chlorideconcentration is measured using a charged aerosol detector.

FIG. 8 provides a graphic representation of chloride concentrationlevels for two batches of SBE_(6.6)-β-CD during ultrafiltration, at theend of ultrafiltration processing, 5, 10, and 20 minutes after additionto the first activated carbon column, and 5, 10, and 20 minutes afteraddition to the second activated carbon column as measured using acharged aerosol detector.

FIG. 9 provides a graphic representation of the level of residualchloride after (a) the first activated carbon column (labeled small) andafter (b) the second activated carbon column (labeled large) measuredusing ion chromatography versus the residual conductivity level (labeledZIC pHILIC % CO of the final SBE_(6.6)-β-CD product measured using a ZICpHILIC column utilizing a charged aerosol detector (Batch Nos.17CX01.HQ00056-17CX01.HQ00064).

FIG. 10 provides a graphic representation of the sodium chlorideconcentration (w/w) of SBE_(6.6)-β-CD samples after (a) one activatedcarbon treatment cycle (Batch Nos. 17CX01.HQ00001-17CX001.HQ00003,17CX01.HQ00004.02, and 17CX01.HQ00005-17CX01.HQ00034) and (b) twoactivated carbon treatment cycles (Batch Nos.17CX01.HQ00035-17CX01.HQ00079) measured using ion chromatography. Thelimit of detection for the ion chromatograph is 0.05% by weight ofchloride.

DETAILED DESCRIPTION OF THE INVENTION

The invention includes combinations and sub-combinations of the variousaspects and embodiments disclosed herein. Further, when a particularfeature, structure, or characteristic is described in connection with anembodiment, it is understood that it is within the knowledge of oneskilled in the art to affect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed. These and other aspects of this invention will be apparentupon reference to the following detailed description, examples, claimsand attached figures.

As used herein, percentages refer to “% by weight” and/or “w/w” (weightby weight concentration) unless otherwise indicated.

References to spatial descriptions (e.g., “above,” “below,” “up,”“down,” “top,” “bottom,” etc.) made herein are for purposes ofdescription and illustration only, and should be interpreted asnon-limiting upon the processes, equipment, compositions and products ofany method of the present invention, which can be spatially arranged inany orientation or manner.

Alkylated Cyclodextrin

An “alkylated cyclodextrin composition” is a composition comprisingalkylated cyclodextrins having a degree of substitution or an averagedegree of substitution (ADS) for a specified substituent. An alkylatedcyclodextrin composition comprises a distribution of alkylatedcyclodextrin species differing in the individual degree of substitutionspecified substituent for each species, wherein the specifiedsubstituent for each species is the same. As used herein, an “alkylatedcyclodextrin composition” is a substantially pharmaceutically inactivecomposition (i.e., a composition which does not contain apharmaceutically active agent). For example, a cyclodextrin compositionmay comprise at least 90% (w/w) cyclodextrin, at least 95% (w/w)cyclodextrin, at least 97% (w/w) cyclodextrin, at least 99% (w/w)cyclodextrin, at least 99.9% (w/w) cyclodextrin, or at least 99.99%(w/w) cyclodextrin.

The alkylated cyclodextrin can be a water soluble alkylatedcyclodextrin, which is any alkylated cyclodextrin exhibiting enhancedwater solubility over its corresponding underivatized parentcyclodextrin and having a molecular structure based upon α-, orγ-cyclodextrin. In some embodiments, a derivatized cyclodextrin preparedby a process of the present invention has a solubility in water of 100mg/mL or higher, or a solubility in water of less than 100 mg/mL.

The cyclodextrin can be derivatized with neutral, anionic or cationicsubstituents at the C2, C3, or C6 positions of the individualsaccharides forming the cyclodextrin ring. Suitable water solublealkylated cyclodextrins are described herein. The alkylated cyclodextrincan also be a water insoluble alkylated cyclodextrin or a alkylatedcyclodextrin possessing a lower water solubility than its correspondingunderivatized parent cyclodextrin.

As used herein, a “substituent precursor” or “alkylating agent” refersto a compound, reagent, moiety, or substance capable of reacting with an—OH group present on a cyclodextrin. In some embodiments, thederivatized cyclodextrin includes a substituent such as a sulfoalkylether group, an ether group, an alkyl ether group, an alkenyl ethergroup, a hydroxyalkyl ether group, a hydroxyalkenyl ether group, athioalkyl ether group, an aminoalkyl ether group, a mercapto group, anamino group, an alkylamino group, a carboxyl group, an ester group, anitro group, a halo group, an aldehyde group, a 2,3-epoxypropyl group,and combinations thereof. In some embodiments, alkylating agents includean alkyl sultone (e.g., 1,4-butane sultone, 1,5-pentane sultone,1,3-propane sultone, and the like). An alkylated cyclodextrin is acyclodextrin in which one or more —OH groups is replaced with an —O—Rgroup, wherein the R contains an alkyl moiety. For example, the —O—Rgroup can be an alkyl ether or a sulfoalkyl ether.

In some embodiments, alkylated cyclodextrins such as mixed etheralkylated cyclodextrins include, by way of example, those listed Table 1below.

TABLE 1 Mixed ether CD Mixed ether CD derivative derivative Mixed etherCD derivative Sulfobutyl-hydroxybutyl- Sulfopropyl-hydroxybutyl-Sulfoethyl-hydroxybutyl- CD (SBE-HBE-CD) CD (SPE-HBE-CD) CD (SEE-HBE-CD)Sulfobutyl-hydroxypropyl- Sulfopropyl- Sulfoethyl-hydroxypropyl- CD(SBE-HPE-CD) hydroxypropyl-CD (SPE- CD (SEE-HPE-CD) HPE-CD)Sulfobutyl-hydroxyethyl- Sulfopropyl-hydroxyethyl-Sulfoethyl-hydroxyethyl- CD (SBE-HEE-CD) CD (SPE-HEE-CD) CD (SEE-HEE-CD)Sulfobutyl-hydroxybutenyl- Sulfopropyl- Sulfoethyl-hydroxybutenyl- CD(SBE-HBNE-CD) hydroxybutenyl-CD (SPE- CD (SEE-HBNE-CD) HBNE-CD)Sulfobutyl-ethyl Sulfopropyl-ethyl Sulfoethyl-ethyl (SBE-EE-CD)(SPE-EE-CD) (SEE-EE-CD) Sulfobutyl-methyl Sulfopropyl-methylSulfoethyl-methyl (SBE-ME-CD) (SPE-ME-CD) (SEE-ME-CD) Sulfobutyl-propylSulfopropyl-propyl Sulfoethyl-propyl (SBE-PE-CD) (SPE-PE-CD) (SEE-PE-CD)Sulfobutyl-butyl Sulfopropyl-butyl Sulfoethyl-butyl (SBE-BE-CD)(SPE-BE-CD) (SEE-BE-CD) Sulfobutyl-carboxymethyl- Sulfopropyl-Sulfoethyl-carboxymethyl- CD (SBE-CME-CD) carboxymethyl-CD (SPE- CD(SEE-CME-CD) CME-CD) Sulfobutyl-carboxyethyl- Sulfopropyl-carboxyethyl-Sulfoethyl-carboxyethyl-CD CD (SBE-CEE-CD) CD (SPE-CEE-CD) (SEE-CEE-CD)Sulfobutyl-acetate-CD Sulfopropyl-acetate-CD Sulfoethyl-acetate-CD(SBE-AA-CD) (SPE-AA-CD) (SEE-AA-CD) Sulfobutyl-propionate-CDSulfopropyl-propionate-CD Sulfoethyl-propionate-CD (SBE-PA-CD)(SPE-PA-CD) (SEE-PA-CD) Sulfobutyl-butyrate-CD Sulfopropyl-butyrate-CDSulfoethyl-butyrate-CD (SBE-BA-CD) (SPE-BA-CD) (SEE-BA-CD) Sulfobutyl-Sulfopropyl- Sulfoethyl- methoxycarbonyl-CD methoxycarbonyl-CDmethoxycarbonyl-CD (SEE- (SBE-MC-CD) (SPE-MC-CD) MC-CD)Sulfobutyl-ethoxycarbonyl- Sulfopropyl- Sulfoethyl-ethoxycarbonyl- CD(SBE-EC-CD) ethoxycarbonyl-CD (SPE- CD (SEE-EC-CD) EC-CD) Sulfobutyl-Sulfopropyl- Sulfoethyl- propoxycarbonyl-CD propoxycarbonyl-CD (SPE-propoxycarbonyl-CD (SEE- (SBE-PC-CD) PC-CD) PC-CD) Hydroxybutyl-Hydroxypropyl- Hydroxyethyl- hydroxybutenyl-CD (HBE- hydroxybutenyl-CD(HPE- hydroxybutenyl-CD (HEE- HBNE-CD) HBNE-CD) HBNE-CD)Hydroxybutyl-ethyl Hydroxypropyl-ethyl Hydroxyethyl-ethyl (HBE-EE-CD)(HPE-EE-CD) (HEE-EE-CD) Hydroxybutyl-methyl Hydroxypropyl-methylHydroxyethyl-methyl (HBE-ME-CD) (HPE-ME-CD) (HEE-ME-CD)Hydroxybutyl-propyl Hydroxypropyl-propyl Hydroxyethyl-propyl (HBE-PE-CD)(HPE-PE-CD) (HEE-PE-CD) Hydroxybutyl-butyl Hydroxypropyl-butylHydroxyethyl-butyl (HBE-BE-CD) (HPE-BE-CD) (HEE-BE-CD) Hydroxybutyl-Hydroxypropyl- Hydroxyethyl- carboxymethyl-CD carboxymethyl-CDcarboxymethyl-CD (HBE-CME-CD) (HPE-CME-CD) (HEE-CME-CD) Hydroxybutyl-Hydroxypropyl- Hydroxyethyl- carboxyethyl-CD carboxyethyl-CD (HPE-carboxyethyl-CD (HEE- (HBE-CEE-CD) CEE-CD) CEE-CD)Hydroxybutyl-acetate-CD Hydroxypropyl-acetate-CD Hydroxyethyl-acetate-CD(HBE-AA-CD) (HPE-AA-CD) (HEE-AA-CD) Hydroxybutyl-propionate-Hydroxypropyl-propionate- Hydroxyethyl-propionate- CD (HBE-PA-CD) CD(HPE-PA-CD) CD (HEE-PA-CD) Hydroxybutyl-butyrate-CDHydroxypropyl-butyrate- Hydroxyethyl-butyrate-CD (HBE-BA-CD) CD(HPE-BA-CD) (HEE-BA-CD) Hydroxybutyl- Hydroxypropyl- Hydroxyethyl-methoxycarbonyl-CD methoxycarbonyl-CD methoxycarbonyl-CD (HBE-MC-CD)(HPE-MC-CD) (HEE-MC-CD) Hydroxybutyl- Hydroxypropyl- Hydroxyethyl-ethoxycarbonyl-CD (HBE- ethoxycarbonyl-CD ethoxycarbonyl-CD EC-CD)(HPE-EC-CD) (HEE-EC-CD) Hydroxybutyl- Hydroxypropyl- Hydroxyethyl-propoxycarbonyl-CD propoxycarbonyl-CD propoxycarbonyl-CD (HBE-PC-CD)(HPE-PC-CD) (HEE-PC-CD) Hydroxybutenyl-ethyl Hydroxypropenyl-ethylHydroxypentenyl-ethyl (HBNE-EE-CD) (HPNE-EE-CD) (HPTNE-EE-CD)Hydroxybutenyl-methyl Hydroxypropenyl-methyl Hydroxypentenyl-methyl(HBNE-ME-CD) (HPNE-ME-CD) (HPTNE-ME-CD) Hydroxybutenyl-propylHydroxypropenyl-propyl Hydroxypentenyl-propyl (HBNE-PE-CD) (HPNE-PE-CD)(HPTNE-PE-CD) Hydroxybutenyl-butyl Hydroxypropenyl-butylHydroxypentenyl-butyl (HBNE-BE-CD) (HPNE-BE-CD) (HPTNE-BE-CD)Hydroxybutenyl- Hydroxypropenyl- Hydroxypentenyl- carboxymethyl-CDcarboxymethyl-CD carboxymethyl-CD (HBNE-CME-CD) (HPNE-CME-CD)(HPTNE-CME-CD) Hydroxybutenyl- Hydroxypropenyl- Hydroxypentenyl-carboxyethyl-CD carboxyethyl-CD (HPNE- carboxyethyl-CD (HPTNE-(HBNE-CEE-CD)- CEE-CD) CEE-CD) Hydroxybutenyl-acetate-Hydroxypropenyl-acetate- Hydroxypentenyl-acetate- CD (HBNE-AA-CD) CD(HPNE-AA-CD) CD (HPTNE-AA-CD) Hydroxybutenyl- Hydroxypropenyl-Hydroxypentenyl- propionate-CD (HBNE-PA- propionate-CD propionate-CD CD)(HPNE-PA-CD) (HPTNE-PA-CD) Hydroxybutenyl-butyrate-Hydroxypropenyl-butyrate- Hydroxypentenyl-butyrate- CD (HBNE-BA-CD) CD(HPNE-BA-CD) CD (HPTNE-BA-CD) Hydroxybutenyl- Hydroxypropenyl-Hydroxypentenyl- methoxycarbonyl-CD methoxycarbonyl-CDmethoxycarbonyl-CD (HBNE-MC-CD) (HPNE-MC-CD) (HPTNE-MC-CD)Hydroxybutenyl- Hydroxypropenyl- Hydroxypentenyl- ethoxycarbonyl-CDethoxycarbonyl-CD ethoxycarbonyl-CD (HBNE-EC-CD) (HPNE-EC-CD)(HPTNE-EC-CD) Hydroxybutenyl- Hydroxypropenyl- Hydroxypentenyl-propoxycarbonyl-CD propoxycarbonyl-CD propoxycarbonyl-CD (HBNE-PC-CD)(HPNE-PC-CD) (HPTNE-PC-CD)

After reaction, purification, and/or isolation, the alkylatedcyclodextrin composition of the present invention can comprise smallamounts (e.g., 1% or less, 0.5% or less, 0.1% or less, 0.05% or less,0.001% or less, 0.0005% or less, or 0.0001% or less, by weight) of acyclodextrin starting material (e.g., an underivatized parentcyclodextrin).

The alkylated cyclodextrin can be present in high purity form. See U.S.Patent No. 7,635,773. In some embodiments, the alkylated cyclodextrin isa high purity SAE-CD composition having a reduced amount ofdrug-degrading agent as compared to known commercial lots of CAPTISOL®.The composition optionally has a reduced amount of phosphate or excludesphosphate entirely as compared to known commercial lots of CAPTISOL®.The composition also optionally has lower amounts of a color-formingagent as compared to known commercial lots of CAPTISOL®. The SAE-CDcomposition can also have reduced amounts of 1,4-butane sultone and4-hydroxy-butane-1-sulfonic acid as compared to known commercial lots ofCAPTISOL®.

An alkylated cyclodextrin composition of the present invention providesunexpected advantages over other structurally related alkylatedcyclodextrin compositions. By “structurally related” is meant, forexample, that the substituent of the alkylated cyclodextrin in thecomposition is essentially the same as the substituent of the otheralkylated cyclodextrin to which it is being compared. Exemplaryadvantages can include an enhanced purity, reduced content of pyrogens,reduced content of drug-degrading components, reduced content ofcolor-forming agents, reduced content of unreacted substituentprecursor, and/or reduced content of unreacted cyclodextrin startingmaterial. An exemplary advantage also includes a reduced chloridecontent.

A water soluble alkylated cyclodextrin composition can comprise asulfoalkyl ether cyclodextrin (SAE-CD) compound, or mixture ofcompounds, of the Formula I:

wherein: n is 4, 5 or 6; wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈ and R₉are independently —H, a straight-chain or branched C₁-C₈-(alkylene)-SO₃⁻ group, or an optionally substituted straight-chain or branched C₁-C₆group; wherein at least one of R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈ and R₉ isa straight-chain or branched C₁-C₈-(alkylene)-SO₃ ⁻ group.

In some embodiments, a SAE-CD composition comprises a water-solublealkylated cyclodextrin of Formula II:

wherein: p is 4, 5 or 6;R₁ is independently selected at each occurrence from —OH or -SAE-T;-SAE- is a —O—(C₂-C₆ alkylene)-SO₃ ⁻ group, wherein at least one SAE isindependently a —O—(C₂-C₆ alkylene)-SO₃ ⁻ group, a —O—(CH₂)_(g)SO₃ ⁻group, wherein g is 2 to 6, or 2 to 4, (e.g. —OCH₂CH₂CH₂SO₃ ⁻ or—OCH₂CH₂CH₂CH₂SO₃ ⁻); and -T is independently selected at eachoccurrence from the group consisting of pharmaceutically acceptablecations, which group includes, for example, H⁺, alkali metals (e.g.,Li⁺, Na⁺, K⁺), alkaline earth metals (e.g., Ca⁺², Mg⁺²), ammonium ionsand amine cations such as the cations of (C₁-C₆)-alkylamines,piperidine, pyrazine, (C₁-C₆)-alkanolamine, ethylenediamine and(C₄-C₈)-cycloalkanolamine among others; provided that at least one R₁ isa hydroxyl moiety and at least one R₁ is -SAE-T.

When at least one R₁ of a derivatized cyclodextrin molecule is -SAE-T,the degree of substitution, in terms of the -SAE-T moiety, is understoodto be at least one (1). When the term -SAE- is used to denote asulfoalkyl-(alkylsulfonic acid)-ether moiety it being understood thatthe -SAE- moiety comprises a cation (-T) unless otherwise specified.Accordingly, the terms “SAE” and “-SAE-T” can, as appropriate, be usedinterchangeably herein.

Since SAE-CD is a poly-anionic cyclodextrin, it can be provided indifferent salt forms. Suitable counterions include cationic organicatoms or molecules and cationic inorganic atoms or molecules. The SAE-CDcan include a single type of counterion or a mixture of differentcounterions. The properties of the SAE-CD can be modified by changingthe identity of the counterion present. For example, a first salt formof a SAE-CD composition can possess greater osmotic potential or greaterwater activity reducing power than a different second salt form of sameSAE-CD.

In some embodiments, a sulfoalkyl ether cyclodextrin is complexed withone or more pharmaceutically acceptable cations selected from, e.g., H⁺,alkali metals (e.g., Li⁺, Na⁺, K⁺), alkaline earth metals (e.g., Ca⁺²,Mg⁺²), ammonium ions and amine cations such as the cations of(C₁-C₆)-alkylamines, piperidine, pyrazine, (C₁-C₆)-alkanolamine,ethylenediamine and (C₄-C₈)-cycloalkanolamine, and the like, andcombinations thereof.

Further exemplary sulfoalkyl ether (SAE)-CD derivatives include:

TABLE 2 SAE_(x)-α-CD SAE_(x)-β-CD SAE_(x)-γ-CD (Sulfoethylether)_(x)-α-CD (Sulfoethyl ether)_(x)-β-CD (Sulfoethyl- ether)_(x)-γ-CD(Sulfopropyl ether)_(x)-α-CD (Sulfopropyl ether)_(x)-β-CD (Sulfopropyl-ether)_(x)-γ-CD (Sulfobutyl ether)_(x)-α-CD (Sulfobutyl ether)_(x)-β-CD(Sulfobutyl- ether)_(x)-γ-CD (Sulfopentyl ether)_(x)-α-CD (Sulfopentylether)_(x)-β-CD (Sulfopentyl- ether)_(x)-γ-CD (Sulfohexylether)_(x)-α-CD (Sulfohexyl ether)_(x)-β-CD (Sulfohexyl- ether)_(x)-γ-CD

wherein x denotes the average degree of substitution. In someembodiments, the alkylated cyclodextrins are formed as salts.

Various embodiments of a sulfoalkyl ether cyclodextrin includeeicosa-O-(methyl)-6G-O-(4-sulfobutyl)-(3-cyclodextrin,heptakis-O-(sulfomethyl)-tetradecakis-O-(3-sulfopropyl)-(3-cyclodextrin,heptakis-O-[(1,1-dimethylethyl)dimethylsilyl]-tetradecakis-O-(3-sulfopropyl)-β-cyclodextrin,heptakis-O-(sulfomethyl)-tetradecakis-O-(3-sulfopropyl)-β-cyclodextrin,andheptakis-O-[(1,1-dimethylethyl)dimethylsilyl]-tetradecakis-O-(sulfomethyl)-β-cyclodextrin.Other known alkylated cyclodextrins containing a sulfoalkyl moietyinclude sulfoalkylthio and sulfoalkylthioalkyl ether derivatives such asoctakis-(S-sulfopropyl)-octathio-γ-cyclodextrin,octakis-O-[3-[(2-sulfoethyl)thio]propyl]-β-cyclodextrin], andoctakis-S-(2-sulfoethyl)-octathio-γ-cyclodextrin.

In some embodiments, an alkylated cyclodextrin composition of thepresent invention is a sulfoalkyl ether-β-cyclodextrin compositionhaving an ADS of 2 to 9, 4 to 8, 4 to 7.5, 4 to 7, 4 to 6.5, 4.5 to 8,4.5 to 7.5, 4.5 to 7, 5 to 8, 5 to 7.5, 5 to 7, 5.5 to 8, 5.5 to 7.5,5.5 to 7, 5.5 to 6.5, 6 to 8, 6 to 7.5, 6 to 7.1, 6.5 to 7.1, 6.2 to6.9, or 6.5 per alkylated cyclodextrin, and the remaining substituentsare —H.

In some embodiments, the alkylated cyclodextrin is a compound of FormulaIII:

wherein n is 4, 5 or 6, wherein R₁, R₂, R₃, R₄, R₅, R₆, R₇, R₈ and R₉are independently selected from: —H, a straight-chain or branchedC₁-C₈-(alkylene)-SO₃ ⁻ group, and an optionally substitutedstraight-chain or branched C₁-C₆ group.

A water soluble alkylated cyclodextrin composition can comprise an alkylether (AE)-cyclodextrin compound, or mixture of compounds, of theFormula IV:

wherein: m is 4, 5 or 6; R is independently selected at each occurrencefrom the group consisting of —OH and AE; and AE is —O—(C₁-C₆ alkyl);provided that at least one R is —OH; and at least one AE is present.

Further exemplary AE-CD derivatives include:

TABLE 3 (Alkylether)_(y)-α-CD (Alkylether)_(y)-β-CD(Alkylether)_(y)-γ-CD ME_(y)-α-CD ME_(y)-β-CD ME_(y)-γ-CD EE_(y)-α-CDEE_(y)-β-CD EE_(y)-γ-CD PE_(y)-α-CD PE_(y)-β-CD PE_(y)-γ-CD BE_(y)-α-CDBE_(y)-β-CD BE_(y)-γ-CD PtE_(y)-α-CD PtE_(y)-β-CD PtE_(y)-γ-CDHE_(y)-α-CD HE_(y)-β-CD HE_(y)-γ-CDwherein ME denotes methyl ether, EE denotes ethyl ether, PE denotespropyl ether, BE denotes butyl ether, PtE denotes pentyl ethyl, HEdenotes hexyl ether, and y denotes the average degree of substitution.

A water soluble alkylated cyclodextrin composition can comprise aHAE-cyclodextrin compound, or mixture of compounds, of the Formula V:

wherein: “v” is 4, 5 or 6; “Q” is independently selected at eachoccurrence from the group consisting of —OH, and -HAE; and HAE isHO(C₁-C₆ alkyl)-O—, provided that at least one -HAE moiety is present.

Further exemplary hydroxyalkyl ether (HAE)-CD derivatives include:

TABLE 4 (HAE)_(z)-α-CD (HAE)_(z)-β-CD (HAE)_(z)-γ-CD HMEz-α-CD HMEz-β-CDHMEz-γ-CD HEEz-α-CD HEEz-β-CD HEEz-γ-CD HPEz-α-CD HPEz-β-CD HPEz-γ-CDHBEz-α-CD HBEz-β-CD HBEz-γ-CD HPtEz-α-CD HPtEz-β-CD HPtEz-γ-CD HHEz-α-CDHHEz-β-CD HHEz-γ-CD

wherein HME denotes hydroxymethyl ether, HEE denotes hydroxyethyl ether,HPE denotes hydroxypropyl ether, HBE denotes hydroxybutyl ether, HPtEdenotes hydroxypentyl ether, HHE denotes hydroxyhexyl ether, and zdenotes the average degree of substitution.

A water soluble alkylated cyclodextrin composition can comprise aSAE-AE-CD compound, or mixture of compounds, of Formula VI:

wherein: “v” is 4, 5 or 6; “A” is independently selected at eachoccurrence from the group consisting of —OH, -SAET and -AE; x is thedegree of substitution for the SAET moiety and is 1 to 3v+5; y is thedegree of substitution for the AE moiety and is 1 to 3v+5; -SAE is—O—(C₂-C₆ alkylene)-SO₃ ⁻; T is independently at each occurrence acation; and AE is —O—(C₁-C₃ alkyl); provided that at least one -SAETmoiety and at least one -AE moiety are present; and the sum of x, y andthe total number of —OH groups in an alkylated cyclodextrin is 3v+6.

Specific embodiments of the derivatives of the present invention includethose wherein: 1) the alkylene moiety of the SAE has the same number ofcarbons as the alkyl moiety of the AE; 2) the alkylene moiety of the SAEhas a different number of carbons than the alkyl moiety of the AE; 3)the alkyl and alkylene moieties are independently selected from thegroup consisting of a straight chain or branched moiety; 4) the alkyland alkylene moieties are independently selected from the groupconsisting of a saturated or unsaturated moiety; 5) the ADS for the SAEgroup is greater than or approximates the ADS for the AE group; or 6)the ADS for the SAE group is less than the ADS for the AE group.

A water soluble alkylated cyclodextrin composition can comprise aSAE-HAE-CD compound, or mixture of compounds, of Formula VII:

wherein: “v” is 4, 5 or 6; “X” is independently selected at eachoccurrence from the group consisting of —OH, SAET and HAE; x is thedegree of substitution for the SAET moiety and is 1 to 3w+5; y is thedegree of substitution for the HAE moiety and is 1 to 3w+5; -SAE is—O—(C₂-C₆ alkylene)-SO₃ ⁻; T is independently at each occurrence acation; and HAE is HO—(C₁-C₆ alkyl)-O—; provided that at least one -SAETmoiety and at least one -HAE moiety are present; and the sum of x, y andthe total number of —OH groups in an alkylated cyclodextrin is 3w+6.

The alkylated cyclodextrin can include SAE-CD, HAE-CD, SAE-HAE-CD,HANE-CD, HAE-AE-CD, HAE-SAE-CD, AE-CD, SAE-AE-CD, neutral cyclodextrin,anionic cyclodextrin, cationic cyclodextrin, halo-derivatizedcyclodextrin, amino-derivatized cyclodextrin, nitrile-derivatizedcyclodextrin, aldehyde-derivatized cyclodextrin, carboxylate-derivatizedcyclodextrin, sulfate-derivatized cyclodextrin, sulfonate-derivatizedcyclodextrin, mercapto-derivatized cyclodextrin, alkylamino-derivatizedcyclodextrin, or succinyl-derivatized cyclodextrin.

Within a given alkylated cyclodextrin composition, the substituents ofthe alkylated cyclodextrin(s) thereof can be the same or different. Forexample, SAE or HAE moieties can have the same type or different type ofalkylene (alkyl) radical upon each occurrence in an alkylatedcyclodextrin composition. In such embodiments, the alkylene radical inthe SAE or HAE moiety can be ethyl, propyl, butyl, pentyl or hexyl ineach occurrence in an alkylated cyclodextrin composition.

The alkylated cyclodextrins can differ in their degree of substitutionby functional groups, the number of carbons in the functional groups,their molecular weight, the number of glucopyranose units contained inthe base cyclodextrin used to form the derivatized cyclodextrin and ortheir substitution patterns. In addition, the derivatization of acyclodextrin with functional groups occurs in a controlled, although notexact manner. For this reason, the degree of substitution is actually anumber representing the average number of functional groups percyclodextrin (for example, SBE₇-β-CD has an average of 7 substitutionsper cyclodextrin). Thus, it has an average degree of substitution(“ADS”) of 7. In addition, the regiochemistry of substitution of thehydroxyl groups of the cyclodextrin is variable with regard to thesubstitution of specific hydroxyl groups of the hexose ring. For thisreason, substitution of the different hydroxyl groups is likely to occurduring manufacture of the derivatized cyclodextrin, and a particularderivatized cyclodextrin will possess a preferential, although notexclusive or specific, substitution pattern. Given the above, themolecular weight of a particular derivatized cyclodextrin compositioncan vary from batch to batch.

In a single parent cyclodextrin molecule, there are 3v+6 hydroxylmoieties available for derivatization. Where v=4 (α-cyclodextrin), “y”the degree of substitution for the moiety can range in value from 1 to18. Where v=5 (β-cyclodextrin), “y” the degree of substitution for themoiety can range in value from 1 to 21. Where v=6 (γ-cyclodextrin), “y”the degree of substitution for the moiety can range in value from 1 to24. In general, “y” also ranges in value from 1 to 3v+g, where g rangesin value from 0 to 5. In some embodiments, “y” ranges from 1 to 2v+g, orfrom 1 to 1v+g.

The degree of substitution (“DS”) for a specific moiety (SAE, HAE or AE,for example) is a measure of the number of SAE (HAE or AE) substituentsattached to an individual cyclodextrin molecule, in other words, themoles of substituent per mole of cyclodextrin. Therefore, eachsubstituent has its own DS for an individual alkylated cyclodextrinspecies. The average degree of substitution (“ADS”) for a substituent isa measure of the total number of substituents present per cyclodextrinmolecule for the distribution of alkylated cyclodextrins within analkylated cyclodextrin composition of the present invention. Therefore,SAE₄-CD has an ADS (per CD molecule) of 4.

Some embodiments of the present invention include those wherein: 1) morethan half of the hydroxyl moieties of the alkylated cyclodextrin arederivatized; 2) half or less than half of the hydroxyl moieties of thealkylated cyclodextrin are derivatized; 3) the substituents of thealkylated cyclodextrin are the same upon each occurrence; 4) thesubstituents of the alkylated cyclodextrin comprise at least twodifferent substituents; or 5) the substituents of the alkylatedcyclodextrin comprise one or more of substituents selected from thegroup consisting of unsubstituted alkyl, substituted alkyl, halide(halo), haloalkyl, amine (amino), aminoalkyl, aldehyde, carbonylalkyl,nitrile, cyanoalkyl, sulfoalkyl, hydroxyalkyl, carboxyalkyl, thioalkyl,unsubstituted alkylene, substituted alkylene, aryl, arylalkyl,heteroaryl, and heteroarylalkyl.

Alkylated cyclodextrin compositions can comprise plural individualalkylated cyclodextrin species differing in individual degree ofsubstitution, such that the average degree of substitution iscalculated, as described herein, from the individual degrees ofsubstitution of the species. More specifically, a SAE-CD derivativecomposition can comprise plural SAE-CD species each having a specificindividual degree of substitution with regard to the SAE substituent. Asa consequence, the ADS for SAE of a SAE-CD derivative compositionrepresents an average of the IDS values of the population of individualmolecules in the composition. For example, a SAE_(5.2)-CD compositioncomprises a distribution of plural SAE_(x)-CD molecules, wherein “x”(the DS for SAE groups) can range from 1 to 10-11 for individualcyclodextrin molecules; however, the population of SAE-cyclodextrinmolecules is such that the average value for “x” (the ADS for SAEgroups) is 5.2.

The alkylated cyclodextrin compositions can have a high to moderate tolow ADS. The alkylated cyclodextrin compositions can also have a wide ornarrow “span,” which is the number of individual DS species within analkylated cyclodextrin composition. For example, a alkylatedcyclodextrin composition comprising a single species of alkylatedcyclodextrin having a single specified individual DS is said to have aspan of one, and the individual DS of the alkylated cyclodextrin equalsthe ADS of its alkylated cyclodextrin composition. An electropherogram,for example, of an alkylated cyclodextrin with a span of one should haveonly one alkylated cyclodextrin species with respect to DS. An alkylatedcyclodextrin composition having a span of two comprises two individualalkylated cyclodextrin species differing in their individual DS, and itselectropherogram, for example, would indicate two different alkylatedcyclodextrin species differing in DS. Likewise, the span of an alkylatedcyclodextrin composition having a span of three comprises threeindividual alkylated cyclodextrin species differing in their individualDS. The span of an alkylated cyclodextrin composition typically rangesfrom 5 to 15, or 7 to 12, or 8 to 11.

A parent cyclodextrin includes a secondary hydroxyl group on the C-2 andC-3 positions of the glucopyranose residues forming the cyclodextrin anda primary hydroxyl on the C-6 position of the same. Each of thesehydroxyl moieties is available for derivatization by substituentprecursor. Depending upon the synthetic methodology employed, thesubstituent moieties can be distributed randomly or in a somewhatordered manner among the available hydroxyl positions. Theregioisomerism of derivatization by the substituent can also be variedas desired. The regioisomerism of each composition is independentlyselected. For example, a majority of the substituents present can belocated at a primary hydroxyl group or at one or both of the secondaryhydroxyl groups of the parent cyclodextrin. In some embodiments, theprimary distribution of substituents is C-3>C-2>C-6, while in otherembodiments the primary distribution of substituents is C-2>C-3>C-6.Some embodiments of the present invention include an alkylatedcyclodextrin molecule wherein a minority of the substituent moieties islocated at the C-6 position, and a majority of the substituent moietiesis located at the C-2 and/or C-3 position. Still other embodiments ofthe present invention include an alkylated cyclodextrin molecule whereinthe substituent moieties are substantially evenly distributed among theC-2, C-3, and C-6 positions.

An alkylated cyclodextrin composition comprises a distribution of pluralindividual alkylated cyclodextrin species, each species having anindividual degree of substitution (“IDS”). The content of each of thecyclodextrin species in a particular composition can be quantified usingcapillary electrophoresis. The method of analysis (capillaryelectrophoresis, for example, for charged alkylated cyclodextrins) issufficiently sensitive to distinguish between compositions having only5% of one alkylated cyclodextrin and 95% of another alkylatedcyclodextrin from starting alkylated cyclodextrin compositionscontaining.

The above-mentioned variations among the individual species of alkylatedcyclodextrins in a distribution can lead to changes in the complexationequilibrium constant K_(1:1) which in turn will affect the requiredmolar ratios of the derivatized cyclodextrin to active agent. Theequilibrium constant is also somewhat variable with temperature andallowances in the ratio are required such that the agent remainssolubilized during the temperature fluctuations that can occur duringmanufacture, storage, transport, and use. The equilibrium constant canalso vary with pH and allowances in the ratio can be required such thatthe agent remains solubilized during pH fluctuations that can occurduring manufacture, storage, transport, and use. The equilibriumconstant can also vary due the presence of other excipients (e.g.,buffers, preservatives, antioxidants). Accordingly, the ratio ofderivatized cyclodextrin to active agent can be varied from the ratiosset forth herein in order to compensate for the above-mentionedvariables.

The alkylated cyclodextrins made according to a process of the presentinvention can be employed in compositions, formulations, methods andsystems as such those disclosed in U.S. Pat. Nos. 5,134,127, 5,376,645,5,914,122, 5,874,418, 6,046,177, 6,133,248, 6,153,746, 6,407,079,6,869,939, 7,034,013, 7,625,878, 7,629,331, and 7,635,773; U.S. Pub.Nos. 2005/0164986, 2005/0186267, 2005/0250738, 2006/0258537,2007/0020196, 2007/0020298, 2007/0020299, 2007/0175472, 2007/0202054,2008/0194519, 2009/0011037, 2009/0012042, 2009/0123540; U.S. applicationSer. Nos. 12/404,174, 12/407,734, 61/050,918, 61/177,718, and61/182,560; and PCT International Application Nos. PCT/US06/62346,PCT/US07/71758, PCT/US07/71748, PCT/US07/72387, PCT/US07/72442,PCT/US07/78465, PCT/US08/61697, PCT/US08/61698, PCT/US08/70969, andPCT/US08/82730, the entire disclosures of which are hereby incorporatedby reference. The alkylated cyclodextrins prepared according to theprocesses herein can also be used as suitable substitutes for otherknown grades of alkylated cyclodextrins possessing the same functionalgroups.

In some embodiments, an alkylated cyclodextrin possesses greater watersolubility than a corresponding cyclodextrin from which an alkylatedcyclodextrin composition of the present invention is prepared. Forexample, in some embodiments, an underivatized cyclodextrin is utilizedas a starting material, e.g., α-, β- or γ-cyclodextrin, commerciallyavailable from, e.g., WACKER BIOCHEM CORP. (Adrian, Mich.), and othersources. Underivatized cyclodextrins have limited water solubilitycompared to the alkylated cyclodextrins compositions of the presentinvention. For example, underivatized α-CD, β-CD, γ-CD have a solubilityin water solubility of about 145 g/L, 18.5 g/L, and 232 g/L,respectively, at saturation.

The water-soluble alkylated cyclodextrin composition is optionallyprocessed to remove a major portion (e.g., >50%) of an underivatizedcyclodextrin, or other contaminants.

The terms “alkylene” and “alkyl,” as used herein (e.g., in the—O—(C₂-C₆-alkylene)SO₃ ⁻ group or in the alkylamine cations), includelinear, cyclic, and branched, saturated and unsaturated (i.e.,containing one or more double bonds), divalent alkylene groups andmonovalent alkyl groups, respectively. For example, SAE or HAE moietiescan have the same type or different type of alkylene (alkyl) radicalupon each occurrence in an alkylated cyclodextrin composition. In suchembodiments, the alkylene radical in the SAE or HAE moiety can be ethyl,propyl, butyl, pentyl or hexyl in each occurrence in an alkylatedcyclodextrin composition.

The term “alkanol” in this text likewise includes both linear, cyclicand branched, saturated and unsaturated alkyl components of the alkanolgroups, in which the hydroxyl groups can be situated at any position onthe alkyl moiety. The term “cycloalkanol” includes unsubstituted orsubstituted (e.g., by methyl or ethyl)cyclic alcohols.

In some embodiments, the present invention provides an alkyl ethercyclodextrin (AE-CD) composition, comprising an alkyl ether cyclodextrinhaving an average degree of substitution of 2 to 9, less than 500 ppm ofa phosphate, and less than 0.5% (w/w) of a chloride, wherein the AE-CDcomposition has an absorption of less than 1 A.U., as determined byUV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for anaqueous solution containing 300 mg of the AE-CD composition per mL ofsolution in a cell having a 1 cm path length. In some embodiments, saidabsorption of less than 1 A.U. is due to a drug degrading agent. In someembodiments, the alkyl ether cyclodextrin composition is not asulfobutyl ether cyclodextrin composition. In some embodiments, thealkyl ether cyclodextrin is not a sulfobutyl ether β-cyclodextrin. Insome embodiments, the AE-CD composition has an absorption of 0.5 A.U. orless as determined by UV/vis spectrophotometry at a wavelength of 245 nmto 270 nm for an aqueous solution containing 300 mg of the AE-CDcomposition per mL of solution in a cell having a 1 cm path length. Insome embodiments, said absorption of 0.5 A.U. or less is due to a drugdegrading agent. In some embodiments, the AE-CD composition has anabsorption of 0.2 A.U. or less as determined by UV/vis spectrophotometryat a wavelength of 245 nm to 270 nm for an aqueous solution containing300 mg of the AE-CD composition per mL of solution in a cell having a 1cm path length. In some embodiments, said absorption of 0.2 A.U. or lessis due to a drug degrading agent. In some embodiments, the absorption ofthe AE-CD composition is determined by UV/vis spectrophotometry at awavelength of 245 nm to 270 nm for an aqueous solution containing 500 mgof the AE-CD composition per mL of solution in a cell having a 1 cm pathlength.

In some embodiments, the present invention provides an alkyl ethercyclodextrin (AE-CD) composition, comprising an alkyl ether cyclodextrinhaving an average degree of substitution of 2 to 9, less than 500 ppm ofa phosphate, and less than 0.5% (w/w) of a chloride, wherein the AE-CDcomposition has an absorption of less than 1 A.U., as determined byUV/vis spectrophotometry at a wavelength of 320 nm to 350 nm for anaqueous solution containing 300 mg of the AE-CD composition per mL ofsolution in a cell having a 1 cm path length. In some embodiments, saidabsorption of less than 1 A.U. is due to a color forming agent. In someembodiments, the alkyl ether cyclodextrin composition is not asulfobutyl ether cyclodextrin composition. In some embodiments, thealkyl ether cyclodextrin is not a sulfobutyl ether β-cyclodextrin. Insome embodiments, the AE-CD composition has an absorption of 0.5 A.U. orless as determined by UV/vis spectrophotometry at a wavelength of 320 nmto 350 nm for an aqueous solution containing 300 mg of the SAE-CDcomposition per mL of solution in a cell having a 1 cm path length. Insome embodiments, said absorption of 0.5 A.U. or less is due to a colorforming agent. In some embodiments, the AE-CD composition has anabsorption of 0.2 A.U. or less as determined by UV/vis spectrophotometryat a wavelength of 245 nm to 270 nm for an aqueous solution containing300 mg of the AE-CD composition per mL of solution in a cell having a 1cm path length. In some embodiments, said absorption of 0.2 A.U. or lessis due to a color forming agent. In some embodiments, the absorption ofthe AE-CD composition is determined by UV/vis spectrophotometry at awavelength of 320 nm to 350 nm for an aqueous solution containing 500 mgof the SAE-CD composition per mL of solution in a cell having a 1 cmpath length.

In some embodiments, the average degree of substitution of the AE-CD is4.5 to 7.5. In some embodiments, the average degree of substitution ofthe AE-CD is 6 to 7.5. In some embodiments, the average degree ofsubstitution of the AE-CD is 6.2 to 6.9.

In some embodiments, the present invention provides a compositioncomprising a AE-CD composition and an active agent.

In some embodiments, the present invention provides a sulfoalkyl ethercyclodextrin (SAE-CD) composition, comprising a sulfoalkyl ethercyclodextrin having an average degree of substitution of 2 to 9, lessthan 500 ppm of a phosphate, and less than 0.5% (w/w) of a chloride,wherein the SAE-CD composition has an absorption of less than 1 A.U., asdetermined by UV/vis spectrophotometry at a wavelength of 245 nm to 270nm for an aqueous solution containing 300 mg of the SAE-CD compositionper mL of solution in a cell having a 1 cm path length. In someembodiments, said absorption of less than 1 A.U. is due to a drugdegrading agent. In some embodiments, the sulfoalkyl ether cyclodextrincomposition is not a sulfobutyl ether cyclodextrin composition. In someembodiments, the sulfoalkyl ether cyclodextrin is not a sulfobutyl etherβ-cyclodextrin. In some embodiments, the SAE-CD composition has anabsorption of 0.5 A.U. or less as determined by UV/vis spectrophotometryat a wavelength of 245 nm to 270 nm for an aqueous solution containing300 mg of the SAE-CD composition per mL of solution in a cell having a 1cm path length. In some embodiments, said absorption of 0.5 A.U. or lessis due to a drug degrading agent. In some embodiments, the SAE-CDcomposition has an absorption of 0.2 A.U. or less as determined byUV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for anaqueous solution containing 300 mg of the SAE-CD composition per mL ofsolution in a cell having a 1 cm path length. In some embodiments, saidabsorption of 0.2 A.U. or less is due to a drug degrading agent. In someembodiments, the absorption of the SAE-CD composition is determined byUV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for anaqueous solution containing 500 mg of the SAE-CD composition per mL ofsolution in a cell having a 1 cm path length.

In some embodiments, the sulfoalkyl ether cyclodextrin is a compound ofFormula (II):

wherein p is 4, 5, or 6, and R₁ is independently selected at eachoccurrence from —OH or —O—(C₂-C₆ alkylene)-SO₃ ⁻-T, wherein T isindependently selected at each occurrence from pharmaceuticallyacceptable cations, provided that at least one R₁ is —OH and at leastone R₁ is O—(C₂-C₆ alkylene)-SO₃ ⁻-T. In some embodiments, R₁ isindependently selected at each occurrence from —OH or —O—(C₄alkylene)-SO₃ ⁻-T, and -T is Na⁺ at each occurrence.

In some embodiments, the present invention provides a sulfoalkyl ethercyclodextrin (SAE-CD) composition, comprising a sulfoalkyl ethercyclodextrin having an average degree of substitution of 2 to 9, lessthan 500 ppm of a phosphate, and less than 0.5% (w/w) of a chloride,wherein the SAE-CD composition has an absorption of 1 A.U. or less, asdetermined by UV/vis spectrophotometry at a wavelength of 320 nm to 350nm for an aqueous solution containing 300 mg of the SAE-CD compositionper mL of solution in a cell having a 1 cm path length. In someembodiments, said absorption of 1 A.U. or less is due to a color formingagent. In some embodiments, the sulfoalkyl ether cyclodextrincomposition is not a sulfobutyl ether cyclodextrin composition. In someembodiments, the sulfoalkyl ether cyclodextrin is not a sulfobutyl ether(3-cyclodextrin. In some embodiments, the SAE-CD composition has anabsorption of 0.5 A.U. or less as determined by UV/vis spectrophotometryat a wavelength of 320 nm to 350 nm for an aqueous solution containing300 mg of the SAE-CD composition per mL of solution in a cell having a 1cm path length. In some embodiments, said absorption of 0.5 A.U. or lessis due to a color forming agent. In some embodiments, the SAE-CDcomposition has an absorption of 0.2 A.U. or less as determined byUV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for anaqueous solution containing 300 mg of the SAE-CD composition per mL ofsolution in a cell having a 1 cm path length. In some embodiments, saidabsorption of 0.2 A.U. or less is due to a color forming agent. In someembodiments, the absorption of the SAE-CD composition is determined byUV/vis spectrophotometry at a wavelength of 320 nm to 350 nm for anaqueous solution containing 500 mg of the SAE-CD composition per mL ofsolution in a cell having a 1 cm path length.

In some embodiments, the average degree of substitution of the SAE-CD is4.5 to 7.5. In some embodiments, the average degree of substitution ofthe SAE-CD is 6 to 7.5. In some embodiments, the average degree ofsubstitution of the SAE-CD is 6.2 to 6.9.

In some embodiments, the present invention provides a compositioncomprising a SAE-CD composition and an active agent.

The present invention is also directed to a method for stabilizing anactive agent, the method comprising providing an alkylated cyclodextrincomposition comprising an alkylated cyclodextrin, less than 500 ppm of aphosphate, and less than 0.5% of a chloride, wherein the alkylatedcyclodextrin composition has an absorption of less than 1 A.U., asdetermined by UV/vis spectrophotometry at a wavelength of 245 nm to 270nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution in a cell having a 1 cm pathlength; and combining the alkylated cyclodextrin composition with anactive agent. In some embodiments, said absorption of less than 1 A.U.is due to a drug degrading agent.

The present invention is also directed to a method for stabilizing anactive agent, the method comprising providing an alkylated cyclodextrincomposition comprising an alkylated cyclodextrin, less than 500 ppm of aphosphate, and less than 0.5% of a chloride, wherein the alkylatedcyclodextrin composition has an absorption of less than 1 A.U., asdetermined by UV/vis spectrophotometry at a wavelength of 245 nm to 270nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution in a cell having a 1 cm pathlength; and combining the alkylated cyclodextrin composition with anactive agent. In some embodiments, said absorption of less than 1 A.U.is due to a color forming agent.

The present invention provides a process for preparing an alkylatedcyclodextrin composition, the process comprising:

(a) mixing a cyclodextrin with an alkylating agent in the presence of analkalizing agent to form a reaction milieu comprising an alkylatedcyclodextrin, one or more unwanted components, and one or moredrug-degrading impurities;

(b) conducting one or more separations to remove the one or moreunwanted components from the reaction milieu to form a partiallypurified solution comprising the alkylated cyclodextrin and the one ormore drug-degrading impurities, wherein the one or more separations areultrafiltration, diafiltration, centrifugation, extraction, solventprecipitation, or dialysis;

(c) treating the partially purified solution with a phosphate-freeactivated carbon having a conductivity of 10 μS or less and producingthe alkylated cyclodextrin.

The term “batch” or “lot” as used herein refers to a discretemanufacturing or processing run from start of the processing run to thefinish of the processing run. In some embodiments, the present inventionprovides a process for preparing more than one lot of an alkylatedcyclodextrin composition comprising an alkylated cyclodextrin, theprocess comprising: (a) mixing a cyclodextrin with an alkylating agentto form a reaction milieu comprising an alkylated cyclodextrin, one ormore unwanted components, and one or more drug-degrading impurities; (b)conducting one or more separations to remove the one or more unwantedcomponents from the reaction milieu to form a partially purifiedsolution comprising the alkylated cyclodextrin and the one or moredrug-degrading impurities, wherein the one or more separations areultrafiltration, diafiltration, centrifugation, extraction, solventprecipitation, or dialysis; (c) treating the partially purified solutionwith a phosphate-free activated carbon having a residual conductivity of10 μS or less and producing a lot of an alkylated cyclodextrin; and (d)repeating (a)-(c) to obtain another lot of an alkylated cyclodextrincomposition.

In some embodiments, the more than one lot of an alkylated cyclodextrincomposition is at least 4 lots, at least 5 lots, at least 6 lots, atleast 7 lots, at least 8 lots, at least 9 lots, at least 10 lots, atleast 11 lots, at least 12 lots, at least 13 lots, at least 14 lots, atleast 15 lots, at least 16 lots, at least 17 lots, at least 18 lots, atleast 19 lots, at least 20 lots, at least 30 lots, at least 40 lots, atleast 50 lots, at least 60 lots, at least 70 lots, at least 80 lots, atleast 90 lots, or at least 100 lots. In some embodiments, the more thanone lot of an alkylated cyclodextrin composition is 4 to 100 lots, 10 to100 lots, 20 to 100 lots, 30 to 100 lots, 40 to 100 lots, 50 to 100lots, 10 to 20 lots, 10 to 30 lots, 10 to 40 lots, or 10 to 50 lots.

In some embodiments, 50% or more of the lots of the alkylatedcyclodextrin composition have a chloride level of less than 0.1% (w/w),65% or more of the lots of the alkylated cyclodextrin composition have achloride level of less than 0.1% (w/w), 75% or more of the lots of thealkylated cyclodextrin composition have a chloride level of less than0.1% (w/w), 80% or more of the lots of the alkylated cyclodextrincomposition have a chloride level of less than 0.1% (w/w), 85% or moreof the lots of the alkylated cyclodextrin composition have a chloridelevel of less than 0.1% (w/w), 90% or more of lots of the alkylatedcyclodextrin composition have a chloride level of less than 0.1% (w/w),95% or more of the lots of the alkylated cyclodextrin composition have achloride level of less than 0.1% (w/w), 98% or more of the lots of thealkylated cyclodextrin composition have a chloride level of less than0.1% (w/w), 50% or more of the lots of the alkylated cyclodextrincomposition have a chloride level of less than 0.08% (w/w), 65% or moreof the lots of the alkylated cyclodextrin composition have a chloridelevel of less than 0.08% (w/w), 75% or more of the lots of the alkylatedcyclodextrin composition have a chloride level of less than 0.08% (w/w),80% or more of the lots of the alkylated cyclodextrin composition have achloride level of less than 0.08% (w/w), 85% or more of the lots of thealkylated cyclodextrin composition have a chloride level of less than0.08% (w/w), 90% or more of the lots of the alkylated cyclodextrincomposition have a chloride level of less than 0.08% (w/w), 95% or moreof the lots of the alkylated cyclodextrin composition have a chloridelevel of less than 0.08% (w/w), 98% or more of the lots of the alkylatedcyclodextrin composition have a chloride level of less than 0.08% (w/w),50% or more of the lots of the alkylated cyclodextrin composition have achloride level of less than 0.05% (w/w), 65% or more of the lots of thealkylated cyclodextrin composition have a chloride level of less than0.05% (w/w), 75% or more of the lots of the alkylated cyclodextrincomposition have a chloride level of less than 0.05% (w/w), 80% or moreof the lots of the alkylated cyclodextrin composition have a chloridelevel of less than 0.05% (w/w), 85% or more of the lots of the alkylatedcyclodextrin composition have a chloride level of less than 0.05% (w/w),90% or more of the lots of the alkylated cyclodextrin composition have achloride level of less than 0.05% (w/w), 95% or more of the lots of thealkylated cyclodextrin composition have a chloride level of less than0.05% (w/w), or 98% or more of the lots of the alkylated cyclodextrincomposition have a chloride level of less than 0.05% (w/w).

In some embodiments, the lots of the alkylated cyclodextrin compositionare prepared sequentially.

Preparation of Alkylated Cyclodextrin Compositions

The present invention describes several methods for preparing analkylated cyclodextrin composition. In general, an underivatizedcyclodextrin starting material in neutral to alkaline aqueous media isexposed to substituent precursor. The substituent precursor can be addedincrementally or as a bolus, and the substituent precursor can be addedbefore, during, or after exposure of the cyclodextrin starting materialto the optionally alkaline aqueous media. Additional alkaline materialor buffering material can be added as needed to maintain the pH within adesired range. The derivatization reaction can be conducted at ambientto elevated temperatures. Once derivatization has proceeded to thedesired extent, the reaction is optionally quenched by addition of anacid. The reaction milieu is further processed (e.g., solventprecipitation, filtration, centrifugation, evaporation, concentration,drying, chromatography, dialysis, and/or ultrafiltration) to removeundesired materials and form the target composition. After finalprocessing, the composition can be in the form of a solid, liquid,semi-solid, gel, syrup, paste, powder, aggregate, granule, pellet,compressed material, reconstitutable solid, suspension, glass,crystalline mass, amorphous mass, particulate, bead, emulsion, or wetmass.

The invention provides a process of making an alkylated cyclodextrincomposition comprising an alkylated cyclodextrin, optionally having apre-determined degree of substitution, the process comprising: combiningan unsubstituted cyclodextrin starting material with an alkylating agentin an amount sufficient to effect the pre-determined degree ofsubstitution, in the presence of an alkali metal hydroxide; conductingalkylation of the cyclodextrin within a pH of 9 to 11 until residualunreacted cyclodextrin is less than 0.5% by weight, or less than 0.1%;adding additional hydroxide in an amount sufficient to achieve thedegree of substitution and allowing the alkylation to proceed tocompletion; and adding additional hydroxide to destroy any residualalkylating agent.

Adding an additional hydroxide can be conducted using a quantity ofhydroxide, and under conditions (i.e., amount of additional hydroxideadded, temperature, length of time during which the alkylating agenthydrolysis is conducted) such that the level of residual alkylatingagent in the aqueous crude product is reduced to less than 20 ppm orless than 2 ppm.

It is possible that the reaction milieu or the partially purifiedaqueous solution will comprise unreacted alkylating agent. Thealkylating agent can be degraded in situ by adding additional alkalizingagent or by heating a solution containing the agent. Degrading an excessalkylating agent will be required where unacceptable amounts ofalkylating agent are present in the reaction milieu followingtermination of the mixing. The alkylating agent can be degraded in situby adding additional alkalizing agent or by heating a solutioncontaining the agent.

Degrading can be conducted by: exposing the reaction milieu to anelevated temperature of at least 60° C., at least 65° C., or 60° C. to85° C., 60° C. to 80° C., or 60° C. to 95° C. for a period of at least 6hours, at least 8 hours, 8 hours to 12 hours, 6 hours to 72 hours, or 48hours to 72 hours, thereby degrading the alkylating agent in situ andreducing the amount of or eliminating the alkylating agent in theaqueous liquid.

After the reaction has been conducted as described herein, the aqueousmedium containing the alkylated cyclodextrin can be neutralized to a pHof 7 in order to quench the reaction. The solution can then be dilutedwith water in order to lower viscosity, particularly if furtherpurification is to be conducted. Further purifications can be employed,including, but not limited to, diafiltration on an ultrafiltration unitto purge the solution of reaction by-products such as salts (e.g., NaClif sodium hydroxide was employed as the base) and other low molecularweight by-products. The product can further be concentrated byultrafiltration. The product solution can then be treated with activatedcarbon in order to improve its color, reduce bioburden, andsubstantially remove one or more drug degrading impurities. The productcan be isolated by a suitable drying technique such as freeze drying,spray drying, or vacuum drum drying.

The reaction can initially be prepared by dissolving an unsubstitutedα-, β-, or γ-cyclodextrin starting material in an aqueous solution ofbase, usually a hydroxide such as lithium, sodium, or potassiumhydroxide. The base is present in a catalytic amount (i.e., a molarratio of less than 1:1 relative to the cyclodextrin), to achieve apre-determined or desired degree of substitution. That is, the base ispresent in an amount less than one molar equivalent for each hydroxylsought to be derivatized in the cyclodextrin molecule. Becausecyclodextrins become increasingly soluble in aqueous solution as thetemperature is raised, the aqueous reaction mixture containing base andcyclodextrin should be raised to a temperature of 50° C. to ensurecomplete dissolution. Agitation is generally employed throughout thecourse of the alkylation reaction.

After dissolution is complete, the alkylating agent is added to startthe alkylation reaction. The total amount of alkylating agent addedthroughout the reaction will generally be in excess of thestoichiometric amount required to complete the reaction relative to theamount of cyclodextrin, since some of the alkylating agent is hydrolyzedand/or otherwise destroyed/degraded during the reaction such that it isnot available for use in the alkylation reaction. The exact amount ofalkylating agent to use for a desired degree of substitution can bedetermined through the use of trial runs. The entire amount ofalkylating agent needed to complete the reaction can be added prior toinitiating the reaction. Because the system is aqueous, the reaction isgenerally conducted at a temperature 50° C. and 100° C. The reaction canbe conducted at a temperature less than 100° C., so that specializedpressure equipment is not required. In general, a temperature of 65° C.to 95° C. is suitable.

During the initial phase of the reaction (herein referred to as thepH-control phase), care should be taken to monitor the pH and maintainit at least basic, or in at a pH of 8 to 11. Monitoring of pH can beeffected conventionally as by using a standard pH meter. Adjustment ofthe pH can be effected by adding an aqueous solution of hydroxide, e.g.,a 10-15% solution. During the initial pH-control phase, unreactedcyclodextrin is reacted to the extent that less than 0.5% by weight, orless than 0.1% by weight, of unreacted cyclodextrin remains in solution.Substantially the entire initial charge of cyclodextrin is thus reactedby being partially substituted, but to less than the desiredpre-determined degree of substitution. Residual cyclodextrin can bemonitored throughout this initial phase, for example by HPLC asdescribed below, until a desired endpoint of less than 0.5%, or lessthan 0.1%, of residual cyclodextrin starting material, has beenachieved. The pH can be maintained and/or raised by adding concentratedhydroxide to the reaction medium continuously or in discrete amounts assmall increments. Addition in small increments is particularly suitable.

Once an alkylation procedure has been standardized or optimized so thatit is known that particular amounts of reactants can be combined in aprocedure which produces the desired degree of substitution inconjunction with low residual cyclodextrin, then the procedure cansimply be checked at the end, as opposed to throughout or during theinitial pH-control, to ensure that a low level of residual (unreacted)cyclodextrin starting material has been achieved. The following tablesets forth a relationship between the amount of butane sultone chargedinto a reactor and the resulting average degree of substitution of theSAE-CD.

Butane Sultone Charged Corresponding Approximate (Approximateequivalents of Predetermined BS per mole of cyclodextrin) ADS for SAE-CDformed 2 2 3 3 4 4 5 5 6   5-5.5 7 5.5 to 6.5 8 6.5 to 7   9 7-8 12 8-9

It is noted that the initial pH of the reaction medium can be above 11,for example after combining the initial charge of cyclodextrin startingmaterial and base, but prior to addition of alkylating agent. After analkylating agent has been added and the reaction commences, however, thepH quickly drops, necessitating addition of base to maintain a basic pHof about 8 to about 11.

Once the level of residual unreacted cyclodextrin has reached a desiredlevel, e.g., below 0.5% by weight, during the pH control stage, the pHcan be raised to above 11, for example a level above 12, by addingadditional base to drive the reaction to completion. The pH can be atleast 12 so that the reaction proceeds at a reasonable rate, but not sohigh that unreacted alkylating agent is hydrolyzed rapidly rather thanreacting with cyclodextrin. During this latter phase of the reaction,additional substitution of the cyclodextrin molecule is effected untilthe pre-determined degree of substitution has been attained. The totalamount of hydroxide added throughout the reaction is typically on theorder of the amount stoichiometrically required plus a 10-20% molarexcess relative to the amount of alkylating agent employed. The additionof more than a 10-20% excess is also feasible. The reaction end point,as noted above, can be detected by HPLC. A suitable temperature is 65°C. to 95° C. The HPLC system typically employs an anion exchangeanalytical column with pulsed amperometric detection (PAD). Elution canbe by gradient using a two-solvent system, e.g., Solvent A being 25 mM(millimolar) aqueous sodium hydroxide, and Solvent B being 1 M sodiumnitrate in 250 mM sodium hydroxide.

Once the alkylation reaction is complete and the low residualcyclodextrin end point has been reached, additional hydroxide can beadded to destroy and/or degrade any residual alkylating agent. Theadditional hydroxide is typically added in an amount of 0.5 to 3 molarequivalents relative to cyclodextrin, and the reaction medium is allowedto continue heating at 65° C. to 95° C., typically for 6 hours to 72hours.

After residual alkylating agent destruction, the resulting crude productcan be additionally treated to produce a final product by being diluted,diafiltered to reduce or rid the product of low molecular weightcomponents such as salts, concentrated, carbon treated, and dried.

The pH is initially monitored to ensure that it remains at 8 to 11 asthe alkyl derivatization reaction proceeds. In this initial stage,addition of a hydroxide to facilitate the alkylation can be staged orstep-wise. Monitoring the pH of the reaction ensures that the reactioncan be controlled such that the entire initial stock of cyclodextrinstarting material is essentially reacted to the extent of effecting, onaverage, at least one alkyl substitution per cyclodextrin molecule. Theentire cyclodextrin reactant is thus consumed at the beginning of theprocess, so that the level of residual (unreacted) cyclodextrin in thecrude product is low, relative to the crude product produced by aprocess which features initially combining the entire stoichiometric orexcess amount of base with cyclodextrin and alkylating agent andallowing the reaction to proceed uncontrolled. After the entire chargeof cyclodextrin starting material has been partially reacted, theremaining hydroxide can be added to drive the reaction to completion byfinishing the alkyl substitution to the pre-determined, desired degree.After the initial charge of cyclodextrin has been consumed in the firstpH-controlled phase, the rate of hydroxide addition is not critical.Thus, the hydroxide can be added (e.g., as a solution) continuously orin discrete stages. In addition, the pH of the reaction medium should bemaintained above about 12 so that the rate of reaction is commerciallyuseful.

Reduction and Removal of Impurities in a Cyclodextrin Composition

Initial pH control provides a means for reducing certain by-productsfrom the reaction mixture. For example, an acid is produced as a resultof the alkylation and the pH of the reaction mixture tends to decrease(i.e., become more acidic) as the reaction proceeds. On one hand, thereaction is maintained basic because if the reaction medium becomesacidic, then the reaction will slow considerably or stop. Accordingly,the pH of the reaction medium should be maintained at a level of atleast 8 by adding aqueous hydroxide as needed. On the other hand, if thepH is allowed to exceed a certain level, for example, a pH greater than12, then the reaction can produce a high level of by-products such as4-hydroxyalkylsulfonate and bis-sulfoalkyl ether, thus consuming thealkylating agent starting material. By monitoring the pH of the reactionsolution and maintaining the pH at 8 to 12, or 8 to 11, the reactionproceeds while producing a relatively low-level of by-products, and arelatively clean reaction mixture containing relatively low levels ofthe aforementioned by-products is provided.

Reference above to a reactant being provided in an amount which is“stoichiometrically sufficient,” and the like, is with respect to theamount of reactant needed to fully derivatize the cyclodextrin ofinterest to a desired degree of substitution. As used herein, an “alkalimetal hydroxide” refers to LiOH, NaOH, KOH, and the like. If it isdesired to produce a product suitable for parenteral administration,then NaOH can be used.

The degree of substitution can be controlled by using correspondinglylower or higher amounts of alkylating agent, depending upon whether alower or higher degree of substitution is desired. Generally, the degreeof substitution that can be achieved is an average of from 4.5 to 7.5,5.5 to 7.5, or 6 to 7.1.

The crude product of the process herein, i.e., the product obtainedfollowing residual alkylating agent destruction, contains a lower levelof residual cyclodextrin than that produced by a process in which thebase is initially added in a single charge, and is provided as a furtherfeature of the invention. The crude product produced by the process ofthis invention typically contains less than 0.5% by weight residualcyclodextrin, or less than 0.1%. As explained below, the crude productis also advantageous in that it contains very low residual alkylatingagent levels.

Typically, the crude aqueous cyclodextrin product solution obtainedfollowing residual alkylating agent destruction is purified byultrafiltration, a process in which the crude product is contacted witha semipermeable membrane that passes low molecular weight impuritiesthrough the membrane. The molecular weight of the impurities passedthrough the membrane depends on the molecular weight cut-off for themembrane. For the instant invention, a membrane having a molecularweight cutoff of 1,000 Daltons (“Da”) is typically employed.Diafiltrations and/or ultrafiltrations can be conducted with filtrationmembranes having a molecular weight cut-off of 500 Da to 2,000 Da, 500Da to 1,500 Da, 750 Da to 1,250 Da, or 900 Da to 1,100 Da, or about1,000 Da. The desired product which is in the retentate is then furthertreated with activated carbon to substantially remove drug-degradingimpurities. The crude aqueous cyclodextrin product solution (i.e.,obtained after residual alkylating agent destruction but beforepurification) is advantageous in that it contains less than 2 ppmresidual alkylating agent based on the weight of the solution, less than1 ppm, or less than 250 ppb. The crude solution can also containessentially no residual alkylating agent.

A final, commercial product can be isolated at this point by, e.g.,filtration to remove the activated carbon, followed by evaporation ofthe water (via, e.g., distillation, spray dying, lyophilization, and thelike). The final product produced by the instant inventionadvantageously contains very low residual levels of alkylating agent,e.g., less than 2 ppm based on the weight of the dry (i.e., containingless than 10% by weight water) final product, less than 1 ppm, less than250 ppb, or essentially no residual alkylating agent. The final productcontaining less than 250 ppb of alkylating agent is accordingly providedas an additional feature of the invention. The alkylating agent isreduced following completion of the alkylation to the desired degree ofsubstitution by an alkaline hydrolysis treatment as previouslydescribed, i.e., by adding extra hydroxide solution in an amount andunder conditions sufficient to reduce the amount of unreacted alkylatingagent in the dry product to the desired level below 2 ppm, less than 1ppm, or less than 250 ppb.

Activated carbon suitable for use in the process of the presentinvention can be phosphate-free, and can be powder or granular, or asuspension or slurry produced therefrom. Generally, phosphate-freeactivated carbon is a carbon that was not activated using, or otherwiseexposed to, phosphoric acid.

A wide variety of activated carbon is available. For example,Norit-Americas commercializes over 150 different grades and varieties ofactivated carbon under trademarks such as DARCO®, HYDRODARCO®, NORIT®,BENTONORIT®, PETRODARCO®, and SORBONORIT®. The carbons differ inparticle size, application, method of activation, and utility. Forexample, some activated carbons are optimized for color and/or flavorremoval. Other activated carbons are optimized for removal of protein,mineral, and/or amino acid moieties, or for clarifying solutions.

Activated carbons suitable for use according to the present inventioninclude, but are not limited to: DARCO® 4×12, 12×20, or 20×40 granularfrom lignite, steam activated (Norit Americas, Inc., Amersfoort, NE);DARCO® S 51 HF (from lignite, steam activated, powder); and SHIRASAGI®DC-32 powered or granular carbon from wood, zinc chloride activated(Takeda Chemical Industries, Ltd., Osaka, JP).

Carbon that is activated with phosphoric acid, as used in the prior artfor purifying alkyl ether cyclodextrins, is generally unsuitable for usewith the present invention, and includes: DARCO® KB-G, DARCO® KB-B andDARCO® KB-WJ, as well as NORIT® CASP and NORIT® CN1.

In some embodiments, the phosphate level in the alkylated cyclodextrincomposition is less than 200 ppm, less than 150 ppm, less than 125 ppm,less than 100 ppm, less than 95 ppm, less than 90 ppm, less than 85 ppm,less than 80 ppm, less than 75 ppm, less than 70 ppm, less than 65 ppm,less than 60 ppm, less than 55 ppm, less than 50 ppm, less than 45 ppm,less than 40 ppm, less than 35 ppm, less than 30 ppm, less than 25 ppm,less than 20 ppm, less than 15 ppm, less than 10 ppm, or less than 5ppm. In some embodiments, the phosphate level in the alkylatedcyclodextrin composition is 200 ppm to 5 ppm, 150 ppm to 5 ppm, 125 ppmto 5 ppm, 100 ppm to 5 ppm, 75 ppm to 5 ppm, 50 ppm to 5 ppm, 150 ppm to10 ppm, 125 ppm to 10 ppm, 100 ppm to 10 ppm, or 75 ppm to 10 ppm.

The loading ratio of activated carbon ultimately depends upon the amountor concentration of the alkylated cyclodextrin, color-forming agents,and drug-degrading agents in solution as well as the physical propertiesof the activated carbon used. In general, the weight ratio of acyclodextrin to activated carbon is 5:1 to 10:1, 6:1 to 9:1, 7:1 to 9:1,8:1 to 9:1, 8.3:1 to 8.5:1, 8.4:1 to 8.5:1, or 8.44:1 by weight pertreatment cycle.

As used herein, “treatment cycle” refers to a contacting a predeterminedamount of a cyclodextrin composition with a predetermined amount ofactivated carbon. A treatment cycle can be performed as a singletreatment or as a multiple (recycling) pass-through treatment.

The Examples provided herein detail procedures used to evaluate andcompare the efficiency of different grades, lots, sources, and types ofactivated carbon in removing the one or more drug-degrading componentsand one or more color-forming components present in an in-process milieuor solution of SAE-CD. In general, an in-process milieu or solution istreated with activated carbon and agitated for 120 min. If a loose,particulate, or powdered form of activated carbon is used, it can beremoved by filtration of a liquid containing the carbon through afiltration medium to provide the clarified solution.

The filtration membrane can include nylon, TEFLON®, PVDF or anothercompatible material. The pore size of the filtration membrane can bevaried as needed according to the particle size or molecular weight ofspecies being separated from the SAE-CD in a solution containing thesame.

The Examples provided herein detail procedures for conducting one ormore separations and/or purifications on an aqueous reaction milieu ofthe present invention. A reaction solution is diluted with aqueoussolution and subjected to diafiltration during which the volume of theretentate is maintained substantially constant. The diafiltration can beconducted over a 1,000 Da filter such that one or more unwantedcomponents pass through the filter but the majority of the alkyl etherpresent in the alkylated cyclodextrin composition is retained in theretentate rather than passing through with the filtrate. Theultrafiltration is then conducted by allowing the volume of theretentate to decrease thereby concentrating the retentate. A filterhaving a molecular weight cut-off of about 1,000 Da can also be used forthe ultrafiltration. The retentate comprises the alkylated cyclodextrin,which can then be treated with activated carbon as described herein.

The one or more unwanted components can include, but are not limited to,low molecular weight impurities (i.e., impurities having a molecularweight of about 500 Da or less), water-soluble and/or water-insolubleions (i.e., salts), hydrolyzed alkylating agent,5-(hydroxymethyl)-2-furaldehyde, unreacted cyclodextrin startingmaterial, degraded cyclodextrin species (e.g., degraded and/orring-opened species formed from unreacted cyclodextrin, partiallyreacted cyclodextrin, and/or SAE-CD), unreacted alkylating agent (e.g.,1,4-butane sultone), and combinations thereof.

In some embodiments, the compositions of the present invention aresubstantially free of one or more drug degrading agents. The presence ofone or more drug degrading agents can be determined, inter alia, byUV/visible (“UV/vis”) spectrophotometry. As used herein, a “drugdegrading agent” or “drug degrading impurity” refers to a species,moiety, and the like, that degrades certain active components in aqueoussolution. It will be understood that a drug degrading agent may notdegrade all drugs with which an alkylated cyclodextrin composition maybe combined, depending on the chemical structure of the drug and itsdegradation pathways. In some embodiments, a drug-degrading species hasan absorption in the UV/visible region of the spectrum, for example, anabsorption maximum at a wavelength of 245 nm to 270 nm.

The presence of drug degrading agents in the alkylated cyclodextrincomposition can be measured by UV/vis in absorbance units (A.U.). Insome embodiments, the alkylated cyclodextrin composition has anabsorption of less than 1 A.U., less than 0.9 A.U., less than 0.8 A.U.,less than 0.7 A.U., less than 0.6 A.U., 0.5 A.U., less than 0.4 A.U.,less than 0.3 A.U., less than 0.2 A.U., or less than 0.1 A.U.

The absorbance of the solution becomes linear with the concentrationaccording to the formula:

A=εlc

wherein

A=absorbance

ε=extinction coefficient

l=path length

c=molar concentration.

The presence of a drug-degrading agent in the alkylated cyclodextrincomposition can be measured using UV/vis spectrophotometry at awavelength of 245 to 270 nm using a cell having a path length of 1 cm.In some embodiments, the alkylated cyclodextrin composition has anabsorption of less than 1 A.U. at a wavelength of 245 nm to 270 nm foran aqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, less than 1 A.U. at a wavelength of 245nm to 270 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, less than 1 A.U. at awavelength of 245 nm to 270 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, less than1 A.U. at a wavelength of 245 nm to 270 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.9 A.U. or less at a wavelength of 245 nm to 270 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.9 A.U. or less at a wavelength of 245nm to 270 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.9 A.U. or less at awavelength of 245 nm to 270 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.9 A.U.or less at a wavelength of 245 nm to 270 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.8 A.U. or less at a wavelength of 245 nm to 270 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.8 A.U. or less at a wavelength of 245nm to 270 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.8 A.U. or less at awavelength of 245 nm to 270 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.8 A.U.or less at a wavelength of 245 nm to 270 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.7 A.U. or less at a wavelength of 245 nm to 270 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.7 A.U. or less at a wavelength of 245nm to 270 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.7 A.U. or less at awavelength of 245 nm to 270 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.7 A.U.or less at a wavelength of 245 nm to 270 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.6 A.U. or less at a wavelength of 245 nm to 270 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.6 A.U. or less at a wavelength of 245nm to 270 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.6 A.U. or less at awavelength of 245 nm to 270 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.6 A.U.or less at a wavelength of 245 nm to 270 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.5 A.U. or less at a wavelength of 245 nm to 270 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.5 A.U. or less at a wavelength of 245nm to 270 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.5 A.U. or less at awavelength of 245 nm to 270 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.5 A.U.or less at a wavelength of 245 nm to 270 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.4 A.U. or less at a wavelength of 245 nm to 270 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.4 A.U. or less at a wavelength of 245nm to 270 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.4 A.U. or less at awavelength of 245 nm to 270 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.4 orless A.U. at a wavelength of 245 nm to 270 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.3 A.U. or less at a wavelength of 245 nm to 270 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition, 0.3 A.U. or less at a wavelength of 245 nm to 270 nm for anaqueous solution containing 300 mg of the alkylated cyclodextrincomposition per mL of solution, 0.3 A.U. or less at a wavelength of 245nm to 270 nm for an aqueous solution containing 400 mg of the alkylatedcyclodextrin composition per mL of solution, 0.3 A.U. or less at awavelength of 245 nm to 270 nm for an aqueous solution containing 500 mgof the alkylated cyclodextrin composition per mL of solution, 0.2 A.U.or less at a wavelength of 245 nm to 270 nm for an aqueous solutioncontaining 200 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.2 A.U. or less at a wavelength of 245 nm to 270 nm for anaqueous solution containing 300 mg of the alkylated cyclodextrincomposition per mL of solution, 0.2 A.U. or less at a wavelength of 245nm to 270 nm for an aqueous solution containing 400 mg of the alkylatedcyclodextrin composition per mL of solution, or 0.2 A.U. or less at awavelength of 245 nm to 270 nm for an aqueous solution containing 500 mgof the alkylated cyclodextrin composition per mL of solution.

The presence of a color-forming agent in the alkylated cyclodextrincomposition can be measured using UV/vis spectrophotometry at awavelength of 320 nm to 350 nm using a cell having a path length of 1cm. In some embodiments, the alkylated cyclodextrin composition has anabsorption of less than 1 A.U. at a wavelength of 320 nm to 350 nm foran aqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, less than 1 A.U. at a wavelength of 320nm to 350 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, less than 1 A.U. at awavelength of 320 nm to 350 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, less than1 A.U. at a wavelength of 320 nm to 350 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.9 A.U. or less at a wavelength of 320 nm to 350 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.9 A.U. or less at a wavelength of 320nm to 350 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.9 A.U. or less at awavelength of 320 nm to 350 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.9 A.U.or less at a wavelength of 320 nm to 350 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.8 A.U. or less at a wavelength of 320 nm to 350 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.8 A.U. or less at a wavelength of 320nm to 350 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.8 A.U. or less at awavelength of 320 nm to 350 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.8 A.U.or less at a wavelength of 320 nm to 350 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.7 A.U. or less at a wavelength of 320 nm to 350 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.7 A.U. or less at a wavelength of 320nm to 350 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.7 A.U. or less at awavelength of 320 nm to 350 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.7 A.U.or less at a wavelength of 320 nm to 350 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.6 A.U. or less at a wavelength of 320 nm to 350 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.6 A.U. or less at a wavelength of 320nm to 350 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.6 A.U. or less at awavelength of 320 nm to 350 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.6 A.U.or less at a wavelength of 320 nm to 350 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.5 A.U. or less at a wavelength of 320 nm to 350 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.5 A.U. or less at a wavelength of 320nm to 350 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.5 A.U. or less at awavelength of 320 nm to 350 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.5 A.U.or less at a wavelength of 320 nm to 350 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.4 A.U. or less at a wavelength of 320 nm to 350 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition per mL of solution, 0.4 A.U. or less at a wavelength of 320nm to 350 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution, 0.4 A.U. or less at awavelength of 320 nm to 350 nm for an aqueous solution containing 400 mgof the alkylated cyclodextrin composition per mL of solution, 0.4 A.U.or less at a wavelength of 320 nm to 350 nm for an aqueous solutioncontaining 500 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.3 A.U. or less at a wavelength of 320 nm to 350 nm for anaqueous solution containing 200 mg of the alkylated cyclodextrincomposition, 0.3 A.U. or less at a wavelength of 320 nm to 350 nm for anaqueous solution containing 300 mg of the alkylated cyclodextrincomposition per mL of solution, 0.3 A.U. or less at a wavelength of 320nm to 350 nm for an aqueous solution containing 400 mg of the alkylatedcyclodextrin composition per mL of solution, 0.3 A.U. or less at awavelength of 320 nm to 350 nm for an aqueous solution containing 500 mgof the alkylated cyclodextrin composition per mL of solution, 0.2 A.U.or less at a wavelength of 320 nm to 350 nm for an aqueous solutioncontaining 200 mg of the alkylated cyclodextrin composition per mL ofsolution, 0.2 A.U. or less at a wavelength of 320 nm to 350 nm for anaqueous solution containing 300 mg of the alkylated cyclodextrincomposition per mL of solution, 0.2 A.U. or less at a wavelength of 320nm to 350 nm for an aqueous solution containing 400 mg of the alkylatedcyclodextrin composition per mL of solution, or 0.2 A.U. or less at awavelength of 320 nm to 350 nm for an aqueous solution containing 500 mgof the alkylated cyclodextrin composition per mL of solution.

Not being bound by any particular theory, a drug-degrading agent,species, or moiety can include one or more low-molecular weight species(e.g., a species having a molecular weight less than 1,000 Da), such as,but not limited to a species generated as a side-product and/ordecomposition product in the reaction mixture. As such, drug-degradingspecies include, but are not limited to, a glycosidic moiety, aring-opened cyclodextrin species, a reducing sugar, a glucosedegradation product (e.g., 3,4-dideoxyglucosone-3-ene,carbonyl-containing degradants such as 2-furaldehyde,5-hydroxymethyl-2-furaldehyde and the like), and combinations thereof.

In some embodiments, the alkylated cyclodextrin composition comprisesless than 1% wt., less than 0.5% wt., less than 0.2% wt., less than 0.1%wt., less than 0.08% wt., or less than 0.05% wt. of an alkali metalhalide salt.

In some embodiments, the alkylated cyclodextrin composition comprisesless than 1% wt., less than 0.5% wt., less than 0.25% wt., less than0.1% wt., less than 0.08% wt., or less than 0.05% wt. of a hydrolyzedalkylating agent.

In some embodiments, the alkylated cyclodextrin composition comprisesless than 500 ppm, less than 100 ppm, less than 50 ppm, less than 20ppm, less than 10 ppm, less than 5 ppm, less than 2 ppm, less than 1ppm, less than 500 ppb, or less than 250 ppb of an alkylating agent.

In some embodiments, the alkylated cyclodextrin composition comprisesless than 0.5% wt., less than 0.2% wt., less than 0.1% wt., or less than0.08% wt. of underivatized cyclodextrin.

By “complexed” is meant “being part of a clathrate or inclusion complexwith,” i.e., a “complexed” therapeutic agent is part of a clathrate orinclusion complex with an alkylated cyclodextrin. The term “majorportion” refers to 50% or greater, by weight, or on a molar basis. Thus,a formulation according to the present invention can contain an activeagent of which more than about 50% by weight is complexed with analkylated cyclodextrin. The actual percentage of active agent that iscomplexed will vary according to the complexation equilibrium bindingconstant characterizing the complexation of a specific cyclodextrin witha specific active agent. The invention also includes embodiments whereinthe active agent is not complexed with the cyclodextrin or in which onlya minor portion of the active agent is complexed with the alkylatedcyclodextrin. It should be noted that an alkylated cyclodextrin, canform one or more ionic bonds with a positively charged compound. Thisionic association can occur regardless of whether the positively chargedcompound is complexed with the cyclodextrin by inclusion complexation.

As shown in FIG. 6, after ultrafiltration of the crude SBE-CD product,impurities such as β-cyclodextrin and 4-hydroxybutane-1-sulfonic acid(4-HBSA) are present. After a second column with activated carbon, theamount of β-cyclodextrin and 4-hydroxybutane-1-sulfonic acid impuritieshave been reduced. However, as shown in FIG. 6, there are high amountsof chloride present in the product after the two columns.

In the purification process using the activated carbon, althoughdrug-degrading agents have been reduced, high amounts of chloride arepresent in the alkylated cyclodextrin product. This high amount ofchloride in the alkylated cyclodextrin product may react with an activeagent and cause degradation of the active agent. Therefore, it isnecessary to reduce the chloride levels in the alkylated cyclodextrinproduct, in particular when the active agent is sensitive to chloride.

Determining whether an active agent is sensitive to chloride can bedetermined by one of ordinary skill in the art using known techniques.

As shown in FIG. 7, after the ultrafiltration, the residual level ofchloride drops to approximately zero. After further purification usingtwo columns of activated carbon, chloride is added back into the SBE-CDsolution.

During the purification of activated carbon, water is run through theactivated carbon column until the conductivity is at a constant levelbefore adding the SBE-CD solution. The following Table provides detailsof the amount of water and the resulting conductivity levels measuredfor columns of activated carbon. As seen in the Table, even in batcheswhere 70,000 liters of water have been used to wash the activated carbonbefore addition of the SBE-CD solution, a chloride impurity was found inthe final SBE-CD solution.

Column 1 Column 2 Batch No. Water (L) Conductivity (μS) Conductivity(μS) 17CX01F.HQ00075 35,000 17.97 17.7 discarded 70,000 16.01 17.8417CX01F.HQ00076 36,800 18.5 36.3 17CX01F.HQ00077 5,420 52.0 34.717CX01F.HQ00067 7,850 12.74 12.43 17CX01F.HQ00068 7,256 9.72 9.317CX01F.HQ00069 12,131 8.86 5.58 17CX01F.HQ00070 4,670 6.44 8.0517CX01F.HQ00071 6,442 6.4 6.37 17CX01F.HQ00072 7,500 10.98 4.7417CX01F.HQ00073 7,800 13.03 12.45 17CX01F.HQ00074 2,000 4.57 8.3517CX01F.HQ00078 20,630 9.68 13.14

A more extensive examination of the processing before and duringcirculation with the activated carbon shows that the greatest additionof chloride occurs in the first few minutes of circulation of the SBE-CDsolution through the activated carbon bed. As shown in FIG. 8, thechloride impurity level for two SBE-CD commercial batches isapproximately zero after the ultrafiltration and increases substantiallyafter treatment with activated carbon during the first 5 minutes, withthe level dropping after 10 and 20 minutes.

As shown in FIG. 9, there is a direct correlation between the level ofchloride transferred to the SBE-CD solution and the conductivity levelat the end of the water wash. In FIG. 9, the conductivity level in afirst activated carbon column and a second activated carbon column weremeasured. The conductivity levels were found to be correlated with thelevel of residual chloride in the final SBE-CD solid as measured by theZIC pHILIC method for residual chloride content. Therefore, theconductivity measurement obtained at the end of the wash processcorrelates with the level of residual chloride in the final SBE-CDproduct.

The chloride level of the alkylated cyclodextrin composition can bedetermined using any method commonly used by one of skill in the art. Insome embodiments, the chloride level is measured using charged aerosoldetection (CAD).

In some embodiments, the chloride level as measured by weight ratio(w/w) in the alkylated cyclodextrin composition is 1% or less, 0.9% orless, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% orless, 0.3% or less, 0.2% or less, 0.1% or less, 0.09% or less, 0.08% orless, 0.07% or less, 0.06% or less, 0.05% or less, 0.04% or less, 0.03%or less, 0.02% or less, or 0.01% or less. In some embodiments, thechloride level in the alkylated cyclodextrin composition is 1% to 0.01%,0.9% to 0.01%, 0.8% to 0.01%, 0.7% to 0.01%, 0.6% to 0.01%, 0.5% to0.01%, 0.4% to 0.01%, 0.3% to 0.01%, 0.2% to 0.01%, 0.1% to 0.01%, 0.09%to 0.01%, 0.08% to 0.01%, 0.07% to 0.01%, 0.06% to 0.01%, 0.05% to0.01%, 0.04% to 0.01%, or 0.03% to 0.01%.

The conductivity of the activated carbon's water wash eluent can bedetermined using any method commonly used by one of skill in the art. Insome embodiments, the conductivity is measured using a conductivitymeter. In some embodiments, the conductivity is measured using ionchromatography.

In some embodiments, the conductivity of the phosphate-free activatedcarbon's water wash eluent is measured before addition of the partiallypurified alkylated cyclodextrin solution. In some embodiments, theconductivity of the activated carbon's water wash eluent prior toaddition of the partially purified alkylated cyclodextrin solution isless than 35 μS, less than 34 μS, less than 33 μS, less than 32 μS, lessthan 31 μS, less than 30 μS, less than 29 μS, less than 28 μS, less than27 μS, less than 26 μS, less than 25 μS, less than 24 μS, less than 23μS, less than 22 μS, less than 21 μS, less than 20 μS, less than 19 μS,less than 18 μS, less than 17 μS, less than 16 μS, less than 15 μS, lessthan 14 μS, less than 13 μS, less than 12 μS, less than 11 μS, less than10 μS, less than 9 μS, less than 8 μS, less than 7 μS, less than 6 μS,less than 5 μS, less than 4 μS, less than 3 μS, less than 2 μS, or lessthan 1 μS. In some embodiments, the conductivity of the activatedcarbon's water wash eluent prior to addition of the partially purifiedalkylated cyclodextrin solution is 10 μS to 15 μS, 5 μS to 15 μS, 5 μSto 10 μS, 4 μS to 10 μS, 3 μS to 10 μS, or 4 μS to 8 μS.

In some embodiments, the activated carbon is washed 1, 2, 3, 4, 5, 6, 7,8, 9, 10, 11, 12, 13, 14, or 15 times before addition of the partiallypurified alkylated cyclodextrin solution. In some embodiments, theactivated carbon is washed 1 or more, 2 or more, 3 or more, 4 or more, 5or more, 6 or more, 7 or more, 8 or more, 9 or more, or 10 or more timesbefore addition of the partially purified alkylated cyclodextrinsolution.

Even when the activated carbon in the column is washed with water theremay be an inadequate wetting of the activated carbon. In the washprocedure there is no way to control for channeling through the carbonbed. It is believed that by more thoroughly washing the carbon beforecirculating the alkylated cyclodextrin solution it will reduce or removeall further addition of residual chloride from the alkylatedcyclodextrin composition product.

In some embodiments, the activated carbon is added to a dedicated tanksystem with an agitator and screen system. The activated carbon ischarged followed by washing with several portions of water at adetermined agitation rate for a determined time period. Following thewater wash, the water layer is removed from the dedicated tank andadditional water washes occur. After additional water washes theconductivity of the activated carbon is determined and when theconductivity is below a predetermined level the carbon is suspended inwater and pumped into carbon housings. The activated carbon would thenbe ready for addition of the alkylated cyclodextrin solution. Thepredetermined level of conductivity can be, for example, less than 35μS, less than 34 μS, less than 33 μS, less than 32 μS, less than 31 μS,less than 30 μS, less than 29 μS, less than 28 μS, less than 27 μS, lessthan 26 μS, less than 25 μS, less than 24 μS, less than 23 μS, less than22 μS, less than 21 μS, less than 20 μS, less than 19 μS, less than 18μS, less than 17 μS, less than 16 μS, less than 15 μS, less than 14 μS,less than 13 μS, less than 12 μS, less than 11 μS, less than 10 μS, lessthan 9 μS, less than 8 μS, less than 7 μS, less than 6 μS, less than 5μS, less than 4 μS, less than 3 μS, less than 2 μS, or less than 1 μS.

The agitation can be measured in revolutions per minute (rpm). In someembodiments, the agitation rate can range, for example, from 5 rpm to300 rpm. For example, the agitation rate can be 5 rpm, 10 rpm, 20 rpm,30 rpm, 40 rpm, 50 rpm, 60 rpm, 70 rpm, 80 rpm, 90 rpm, or 100 rpm. Theagitation time can range from 1 minute to 5 days. The agitation time canbe, for example, 5 minutes, 10 minutes, 20 minutes, 30 minutes, 40minutes, 50 minutes, 60 minutes, 2 hours, 3 hours, 4 hours, 5 hours, 6hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours, 12 hours, 24hours, 2 days, 3 days, or 4 days. In some embodiments, the agitationtime is 5 minutes to 1 hour, 5 minutes to 2 hours, 5 minutes to 3 hours,5 minutes to 4 hours, 5 minutes to 5 hours, 10 minutes to 1 hour, 10minutes to 2 hours, 10 minutes to 3 hours, 10 minutes to 4 hours, 20minutes to 1 hour, 20 minutes to 2 hours, 20 minutes to 3 hours, 20minutes to 4 hours, 30 minutes to 1 hour, 30 minutes to 2 hours, 30minutes to 3 hours, or 30 minutes to 4 hours.

In some embodiments, the tank system is maintained at room temperature(25° C.) during the water washing process. In some embodiments, the tanksystem can be heated during the water washing process. In someembodiments, the temperature can range, for example, from 30° C. to 100°C. For example, the cooling temperature can be 30° C., 40° C., 50° C.,60° C., 70° C., 80° C., 90° C., or 100° C. The heating time can rangefrom 1 minute to 5 days. The heating time can be, for example, 5 minutesto 4 days, 5 minutes to 60 minutes, 10 minutes to 50 minutes, 20 minutesto 40 minutes, 30 minutes to 60 minutes, 2 hours to 24 hours, 3 hours to12 hours, 4 hours to 10 hours, 5 hours to 9 hours, 6 hours to 8 hours, 2days to 4 days, or 3 days to 4 days. In some embodiments, the heatingtime is 5 minutes to 1 hour, 5 minutes to 2 hours, 5 minutes to 3 hours,5 minutes to 4 hours, 5 minutes to 5 hours, 10 minutes to 1 hour, 10minutes to 2 hours, 10 minutes to 3 hours, 10 minutes to 4 hours, 20minutes to 1 hour, 20 minutes to 2 hours, 20 minutes to 3 hours, 20minutes to 4 hours, 30 minutes to 1 hour, 30 minutes to 2 hours, 30minutes to 3 hours, or 30 minutes to 4 hours.

In some embodiments, the activated carbon is washed in the carbonhousing until a determined conductivity level has been reached. Theactivated carbon would then be ready for addition of the alkylatedcyclodextrin solution.

In some embodiments, the activated carbon is washed to a constantconductivity level followed by addition of a known amount of alkylatedcyclodextrin solution through the activated carbon which is discardedprior to addition of additional alkylated cyclodextrin solution.

The final yield of the alkylated cyclodextrin (in isolated and/orpurified or partially purified form) obtained at completion of theprocess will vary. The final yield of alkylated cyclodextrin based onthe cyclodextrin starting material can range from 10% to 95%, 15% to90%, 20% to 85%, 30% to 85%, 35% to 85%, 40% to 85%, 45% to 80%, 50% to80%, 55% to 80%, 60% to 80%, 50% to 90%, 55% to 90%, 60% to 90%, 70% to90%, 80% to 90%, 60% to 98%, 70% to 98%, 80% to 98%, or 90% to 98%. Insome embodiments, the final yield of alkylated cyclodextrin based on thecyclodextrin starting material is 80% or greater, 85% or greater, 90% orgreater, or 95% or greater.

Uses of Alkylated Cyclodextrin Compositions

Among other uses, an alkylated cyclodextrin composition of the presentinvention can be used to solubilize and/or stabilize a variety ofdifferent materials and to prepare formulations for particularapplications. The present alkylated cyclodextrin composition can provideenhanced solubility and/or enhanced chemical, thermochemical, hydrolyticand/or photochemical stability of other ingredients in a composition.For example, an alkylated cyclodextrin composition can be used tostabilize an active agent in an aqueous medium. An alkylatedcyclodextrin composition can also be used to increase the solubility ofan active agent in an aqueous medium.

The alkylated cyclodextrin composition of the present invention includesone or more active agents. The one or more active agents included in thecomposition of the present invention can possess a wide range of watersolubility, bioavailability and hydrophilicity. Active agents to whichthe present invention is particularly suitable include water insoluble,poorly water-soluble, slightly water-soluble, moderately water-soluble,water-soluble, very water-soluble, hydrophobic, and/or hydrophilictherapeutic agents. It will be understood by a person of ordinary skillin the art one or more active agents present in a composition of thepresent invention is independently selected at each occurrence from anyknown active agent and from those disclosed herein. It is not necessarythat the one or more active agents form a complex with the alkylatedcyclodextrin, or form an ionic association with the alkylatedcyclodextrin.

Active agents generally include physiologically or pharmacologicallyactive substances that produce a systemic or localized effect or effectson animals and human beings. Active agents also include pesticides,herbicides, insecticides, antioxidants, plant growth instigators,sterilization agents, catalysts, chemical reagents, food products,nutrients, cosmetics, vitamins, sterility inhibitors, fertilityinstigators, microorganisms, flavoring agents, sweeteners, cleansingagents, pharmaceutically effective active agents, and other suchcompounds for pharmaceutical, veterinary, horticultural, household,food, culinary, agricultural, cosmetic, industrial, cleaning,confectionery and flavoring applications. The active agent can bepresent in its neutral, ionic, salt, basic, acidic, natural, synthetic,diastereomeric, isomeric, enantiomerically pure, racemic, hydrate,chelate, derivative, analog, or other common form.

Representative pharmaceutically effective active agents includenutrients and nutritional agents, hematological agents, endocrine andmetabolic agents, cardiovascular agents, renal and genitourinary agents,respiratory agents, central nervous system agents, gastrointestinalagents, anti-fungal agents, anti-infective agents, biologic andimmunological agents, dermatological agents, ophthalmic agents,antineoplastic agents, and diagnostic agents. Exemplary nutrients andnutritional agents include as minerals, trace elements, amino acids,lipotropic agents, enzymes and chelating agents. Exemplary hematologicalagents include hematopoietic agents, antiplatelet agents,anticoagulants, coumarin and indandione derivatives, coagulants,thrombolytic agents, antisickling agents, hemorrheologic agents,antihemophilic agents, hemostatics, plasma expanders and hemin.Exemplary endocrine and metabolic agents include sex hormones,uterine-active agents, bisphosphonates, antidiabetic agents, glucoseelevating agents, corticosteroids, adrenocortical steroids, parathyroidhormone, thyroid drugs, growth hormones, posterior pituitary hormones,octreotide acetate, imiglucerase, calcitonin-salmon, sodiumphenylbutyrate, betaine anhydrous, cysteamine bitartrate, sodiumbenzoate and sodium phenylacetate, bromocriptine mesylate, cabergoline,agents for gout, and antidotes. Antifungal agents suitable for use withthe alkylated cyclodextrin composition of the present invention include,but are not limited to, posaconazole, voriconazole, clotrimazole,ketoconazole, oxiconazole, sertaconazole, tetconazole, fluconazole,itraconazole and miconazole. Antipsychotic agents suitable for use withthe alkylated cyclodextrin composition of the present invention include,but are not limited to, clozapine, prochlorperazine, haloperidol,thioridazine, thiothixene, risperidone, trifluoperazine hydrochloride,chlorpromazine, aripiprazole, loxapine, loxitane, olanzapine, quetiapinefumarate, risperidone and ziprasidone.

Exemplary cardiovascular agents include nootropic agents, antiarrhythmicagents, calcium channel blocking agents, vasodilators,antiadrenergics/sympatholytics, renin angiotensin system antagonists,antihypertensive agent combinations, agents for pheochromocytoma, agentsfor hypertensive emergencies, antihyperlipidemic agents,antihyperlipidemic combination products, vasopressors used in shock,potassium removing resins, edetate disodium, cardioplegic solutions,agents for patent ductus arteriosus, and sclerosing agents. Exemplaryrenal and genitourinary agents include interstitial cystitis agents,cellulose sodium phosphate, anti-impotence agents, acetohydroxamic acid(aha), genitourinary irrigants, cystine-depleting agents, urinaryalkalinizers, urinary acidifiers, anticholinergics, urinarycholinergics, polymeric phosphate binders, vaginal preparations, anddiuretics. Exemplary respiratory agents include bronchodilators,leukotriene receptor antagonists, leukotriene formation inhibitors,respiratory inhalant products, nasal decongestants, respiratory enzymes,lung surfactants, antihistamines, normarcotic antitussives, andexpectorants. Exemplary central nervous system agents include CNSstimulants, narcotic agonist analgesics, narcotic agonist-antagonistanalgesics, central analgesics, acetaminophen, salicylates, normarcoticanalgesics, nonsteroidal anti-inflammatory agents, agents for migraine,antiemetic/antivertigo agents, antianxiety agents, antidepressants,antipsychotic agents, cholinesterase inhibitors, nonbarbituratesedatives and hypnotics, nonprescription sleep aids, barbituratesedatives and hypnotics, general anesthetics, injectable localanesthetics, anticonvulsants, muscle relaxants, antiparkinson agents,adenosine phosphate, cholinergic muscle stimulants, disulfuram, smokingdeterrents, riluzole, hyaluronic acid derivatives, and botulinum toxins.Exemplary gastrointestinal agents including H pylori agents, histamineH2 antagonists, proton pump inhibitors, sucralfate, prostaglandins,antacids, gastrointestinal anticholinergics/antispasmodics, mesalamine,olsalazine sodium, balsalazide disodium, sulfasalazine, celecoxib,infliximab, tegaserod maleate, laxatives, antidiarrheals,antiflatulents, lipase inhibitors, GI stimulants, digestive enzymes,gastric acidifiers, hydrocholeretics, gallstone solubilizing agents,mouth and throat products, systemic deodorizers, and anorectalpreparations. Exemplary anti-infective agents including penicillins,cephalosporins and related antibiotics, carbapenem, monobactams,chloramphenicol, quinolones, fluoroquinolones, tetracyclines,macrolides, spectinomycin, streptogramins, vancomycin, oxalodinones,lincosamides, oral and parenteral aminoglycosides, colistimethatesodium, polymyxin b sulfate, bacitracin, metronidazole, sulfonamides,nitrofurans, methenamines, folate antagonists, antifungal agents,antimalarial preparations, antituberculosis agents, amebicides,antiviral agents, antiretroviral agents, leprostatics, antiprotozoals,anthelmintics, and cdc anti-infective agents. Exemplary biologic andimmunological agents including immune globulins, monoclonal antibodyagents, antivenins, agents for active immunization, allergenic extracts,immunologic agents, and antirheumatic agents. Exemplary dermatologicalagents include topical antihistamine preparations, topicalanti-infectives, anti-inflammatory agents, anti-psoriatic agents,antiseborrheic products, arnica, astringents, cleansers, capsaicin,destructive agents, drying agents, enzyme preparations, topicalimmunomodulators, keratolytic agents, liver derivative complex, topicallocal anesthetics, minoxidil, eflornithine hydrochloride,photochemotherapy agents, pigment agents, topical poison ivy products,topical pyrimidine antagonist, pyrithione zinc, retinoids, rexinoids,scabicides/pediculicides, wound healing agents, emollients, protectants,sunscreens, ointment and lotion bases, rubs and liniments, dressings andgranules, and physiological irrigating solutions. Exemplary ophthalmicagents include agents for glaucoma, mast cell stabilizers, ophthalmicantiseptics, ophthalmic phototherapy agents, ocular lubricants,artificial tears, ophthalmic hyperosmolar preparations, and contact lensproducts. Exemplary antineoplastic agents include alkylating agents,antimetabolites, antimitotic agents, epipodophyllotoxins, antibiotics,hormones, enzymes, radiopharmaceuticals, platinum coordination complex,anthracenedione, substituted ureas, methylhydrazine derivatives,imidazotetrazine derivatives, cytoprotective agents, DNA topoisomeraseinhibitors, biological response modifiers, retinoids, rexinoids,monoclonal antibodies, protein-tyrosine kinase inhibitors, porfimersodium, mitotane (o, p′-ddd), and arsenic trioxide. Exemplary diagnosticagents include in vivo diagnostic aids, in vivo diagnostic biologicals,and radiopaque agents.

Exemplary active agents also include compounds that are sensitive tochloride levels. Exemplary chloride sensitive active agents includeproteasome inhibitors such as bortezomib, disulfuram,epigallocatchin-3-gallate, salinosporamide A, and carfilzomib.

The above-listed active agents should not be considered exhaustive andis merely exemplary of the many embodiments considered within the scopeof the invention. Many other active agents can be administered with theformulation of the present invention.

A formulation of the invention can be used to deliver two or moredifferent active agents. Particular combinations of active agents can beprovided in a formulation of the invention. Some combinations of activeagents include: 1) a first drug from a first therapeutic class and adifferent second drug from the same therapeutic class; 2) a first drugfrom a first therapeutic class and a different second drug from adifferent therapeutic class; 3) a first drug having a first type ofbiological activity and a different second drug having about the samebiological activity; and 4) a first drug having a first type ofbiological activity and a different second drug having a differentsecond type of biological activity. Exemplary combinations of activeagents are described herein.

An active agent contained within a formulation of the invention can bepresent as its pharmaceutically acceptable salt. As used herein,“pharmaceutically acceptable salt” refers to derivatives of thedisclosed compounds wherein the active agent is modified by reacting itwith an acid and/or base as needed to form an ionically bound pair.Examples of pharmaceutically acceptable salts include conventionalnon-toxic salts or the quaternary ammonium salts of a compound formed,for example, from non-toxic inorganic or organic acids. Suitablenon-toxic salts include those derived from inorganic acids such ashydrochloric, hydrobromic, sulfuric, sulfonic, sulfamic, phosphoric,nitric and others known to those of ordinary skill in the art. The saltsprepared from organic acids such as amino acids, acetic, propionic,succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic,pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic,salicylic, sulfanilic, 2-acetoxybenzoic, fumaric, toluenesulfonic,methanesulfonic, ethane disulfonic, oxalic, isethionic, and others knownto those of ordinary skill in the art. Pharmaceutically acceptable saltssuitable for use with the present invention can be prepared using anactive agent that includes a basic or acidic group by conventionalchemical methods. Suitable addition salts are found in Remington'sPharmaceutical Sciences (17th ed., Mack Publishing Co., Easton, Pa.,1985), the relevant disclosure of which is hereby incorporated byreference in its entirety.

The present invention is also directed to a method for stabilizing anactive agent, the method comprising providing an alkylated cyclodextrincomposition comprising an alkylated cyclodextrin, less than 500 ppm of aphosphate, and less than 0.5% of a chloride, wherein the alkylatedcyclodextrin composition has an absorption of less than 1 A.U., asdetermined by UV/vis spectrophotometry at a wavelength of 245 nm to 270nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution in a cell having a 1 cm pathlength; and combining the alkylated cyclodextrin composition with anactive agent. In some embodiments, said absorption of less than 1 A.U.is due to a drug degrading agent.

The present invention is also directed to a method for stabilizing anactive agent, the method comprising providing an alkylated cyclodextrincomposition comprising an alkylated cyclodextrin, less than 500 ppm of aphosphate, and less than 0.5% of a chloride, wherein the alkylatedcyclodextrin composition has an absorption of less than 1 A.U., asdetermined by UV/vis spectrophotometry at a wavelength of 245 nm to 270nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution in a cell having a 1 cm pathlength; and combining the alkylated cyclodextrin composition with anactive agent. In some embodiments, said absorption of less than 1 A.U.is due to a color forming agent.

The method of stabilizing an active agent can be performed wherein thecomposition comprising one or more active agents and an alkylatedcyclodextrin composition comprising an alkylated cyclodextrin and lessthan 500 ppm of a phosphate is present as a dry solution, a wetsolution, an inhalable composition, a parenteral composition, a solidsolution, a solid mixture, a granulate, a gel, and other active agentcompositions known to persons of ordinary skill in the art.

In some embodiments, the method of stabilizing an active agent provides2% or less, 1.5% or less, 1% or less, or 0.5% or less of adrug-degrading agent or color-forming agent after the compositioncomprising one or more active agents and an alkylated cyclodextrincomposition comprising an alkylated cyclodextrin and less than 500 ppmof a phosphate is maintained at a temperature of 80° C. for a period of120 minutes.

In some embodiments, the method of stabilizing an active agent provides2% or less, 1.9% or less, 1.8% or less, 1.7% or less, 1.6% or less, 1.5%or less, 1.4% or less, 1.3% or less, 1.2% or less, 1.1% or less, 1% orless, 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% orless, 0.4% or less, 0.3% or less, 0.2% or less, or 0.1% or less of achloride after the composition comprising one or more active agents andan alkylated cyclodextrin composition comprising an alkylatedcyclodextrin and less than 500 ppm of a phosphate is maintained at atemperature of 80° C. for a period of 120 minutes.

Similarly, in some embodiments, the method of stabilizing an activeagent provides an active agent assay of 98% or more, 98.5% or more, 99%or more, or 99.5% or more of the active agent after the compositioncomprising one or more active agents and an alkylated cyclodextrincomposition comprising an alkylated cyclodextrin and less than 500 ppmof a phosphate is maintained at a temperature of 80° C. for a period of120 minutes.

In some embodiments, the method of stabilizing provides an alkylatedcyclodextrin composition comprising an alkylated cyclodextrin with aphosphate level of less than 400 ppm, less than 300 ppm, less than 200ppm, less than 125 ppm, less than 100 ppm, less than 75 ppm, or lessthan 50 ppm.

In some embodiments, the method of stabilizing provides an alkylatedcyclodextrin composition comprising an alkylated cyclodextrin whereinthe alkylated cyclodextrin composition has an absorption of 0.5 A.U. orless, as determined by UV/vis spectrophotometry at a wavelength of 245nm to 270 nm for an aqueous solution containing 300 mg of the alkylatedcyclodextrin composition per mL of solution in a cell having a 1 cm pathlength. In some embodiments, said absorption of 0.5 A.U. or less is dueto a drug degrading agent.

Generally, the alkylated cyclodextrin is present in an amount sufficientto stabilize the active agent. An amount sufficient can be a molar ratioof 0.1:1 to 10:1, 0.5:1 to 10:1, 0.8:1 to 10:1, or 1:1 to 5:1 (alkylatedcyclodextrin:active agent).

A cyclodextrin in the combination composition need not bind with anothermaterial, such as an active agent, present in a formulation containingit. However, if a cyclodextrin binds with another material, such a bondcan be formed as a result of an inclusion complexation, an ion pairformation, a hydrogen bond, and/or a Van der Waals interaction.

An anionic derivatized cyclodextrin can complex or otherwise bind withan acid-ionizable agent. As used herein, the term acid-ionizable agentis taken to mean any compound that becomes or is ionized in the presenceof an acid. An acid-ionizable agent comprises at least oneacid-ionizable functional group that becomes ionized when exposed toacid or when placed in an acidic medium. Exemplary acid-ionizablefunctional groups include a primary amine, secondary amine, tertiaryamine, quaternary amine, aromatic amine, unsaturated amine, primarythiol, secondary thiol, sulfonium, hydroxyl, enol and others known tothose of ordinary skill in the chemical arts.

The degree to which an acid-ionizable agent is bound by non-covalentionic binding versus inclusion complexation formation can be determinedspectrometrically using methods such as ¹H-NMR, ¹³C-NMR, or circulardichroism, for example, and by analysis of the phase solubility data forthe acid-ionizable agent and anionic derivatized cyclodextrin. Theartisan of ordinary skill in the art will be able to use theseconventional methods to approximate the amount of each type of bindingthat is occurring in solution to determine whether or not bindingbetween the species is occurring predominantly by non-covalent ionicbinding or inclusion complex formation. Under conditions wherenon-covalent ionic bonding predominates over inclusion complexformation, the amount of inclusion complex formation, measured by NMR orcircular dichroism, will be reduced even though the phase solubilitydata indicates significant binding between the species under thoseconditions; moreover, the intrinsic solubility of the acid-ionizableagent, as determined from the phase solubility data, will generally behigher than expected under those conditions.

As used herein, the term “non-covalent ionic bond” refers to a bondformed between an anionic species and a cationic species. A bond isnon-covalent such that the two species together form a salt or ion pair.An anionic derivatized cyclodextrin provides the anionic species of theion pair and the acid-ionizable agent provides the cationic species ofthe ion pair. Since an anionic derivatized cyclodextrin is multi-valent,an alkylated cyclodextrin can form an ion pair with one or moreacid-ionizable or otherwise cationic agents.

A liquid formulation of the invention can be converted to a solidformulation for reconstitution. A reconstitutable solid compositionaccording to the invention comprises an active agent, a derivatizedcyclodextrin and optionally at least one other pharmaceutical excipient.A reconstitutable composition can be reconstituted with an aqueousliquid to form a liquid formulation that is preserved. The compositioncan comprise an admixture (minimal to no presence of an inclusioncomplex) of a solid derivatized cyclodextrin and an activeagent-containing solid and optionally at least one solid pharmaceuticalexcipient, such that a major portion of the active agent is notcomplexed with the derivatized cyclodextrin prior to reconstitution.Alternatively, the composition can comprise a solid mixture of aderivatized cyclodextrin and an active agent, wherein a major portion ofthe active agent is complexed with the derivatized cyclodextrin prior toreconstitution. A reconstitutable solid composition can also comprise aderivatized cyclodextrin and an active agent where substantially all orat least a major portion of the active agent is complexed with thederivatized cyclodextrin.

A reconstitutable solid composition can be prepared according to any ofthe following processes. A liquid formulation of the invention is firstprepared, then a solid is formed by lyophilization (freeze-drying),spray-drying, spray freeze-drying, antisolvent precipitation, asepticspray drying, various processes utilizing supercritical or nearsupercritical fluids, or other methods known to those of ordinary skillin the art to make a solid for reconstitution.

A liquid vehicle included in a formulation of the invention can comprisean aqueous liquid carrier (e.g., water), an aqueous alcohol, an aqueousorganic solvent, a non-aqueous liquid carrier, and combinations thereof.

The formulation of the present invention can include one or morepharmaceutical excipients such as a conventional preservative,antifoaming agent, antioxidant, buffering agent, acidifying agent,alkalizing agent, bulking agent, colorant, complexation-enhancing agent,cryoprotectant, electrolyte, glucose, emulsifying agent, oil,plasticizer, solubility-enhancing agent, stabilizer, tonicity modifier,flavors, sweeteners, adsorbents, antiadherent, binder, diluent, directcompression excipient, disintegrant, glidant, lubricant, opaquant,polishing agent, complexing agents, fragrances, other excipients knownby those of ordinary skill in the art for use in formulations,combinations thereof.

As used herein, the term “adsorbent” is intended to mean an agentcapable of holding other molecules onto its surface by physical orchemical (chemisorption) means. Such compounds include, by way ofexample and without limitation, powdered and activated charcoal andother materials known to one of ordinary skill in the art.

As used herein, the term “alkalizing agent” is intended to mean acompound used to provide alkaline medium for product stability. Suchcompounds include, by way of example and without limitation, ammoniasolution, ammonium carbonate, diethanolamine, monoethanolamine,potassium hydroxide, sodium borate, sodium carbonate, sodiumbicarbonate, sodium hydroxide, triethanolamine, diethanolamine, organicamine base, alkaline amino acids and trolamine and others known to thoseof ordinary skill in the art.

As used herein, the term “acidifying agent” is intended to mean acompound used to provide an acidic medium for product stability. Suchcompounds include, by way of example and without limitation, aceticacid, acidic amino acids, citric acid, fumaric acid and other α-hydroxyacids, hydrochloric acid, ascorbic acid, phosphoric acid, sulfuric acid,tartaric acid and nitric acid and others known to those of ordinaryskill in the art.

As used herein, the term “antiadherent” is intended to mean an agentthat prevents the sticking of solid dosage formulation ingredients topunches and dies in a tableting machine during production. Suchcompounds include, by way of example and without limitation, magnesiumstearate, talc, calcium stearate, glyceryl behenate, polyethyleneglycol, hydrogenated vegetable oil, mineral oil, stearic acid and othermaterials known to one of ordinary skill in the art.

As used herein, the term “binder” is intended to mean a substance usedto cause adhesion of powder particles in solid dosage formulations. Suchcompounds include, by way of example and without limitation, acacia,alginic acid, carboxymethylcellulose sodium, poly(vinylpyrrolidone), acompressible sugar, ethylcellulose, gelatin, liquid glucose,methylcellulose, povidone and pregelatinized starch and other materialsknown to one of ordinary skill in the art.

When needed, binders can also be included in the dosage forms. Exemplarybinders include acacia, tragacanth, gelatin, starch, cellulose materialssuch as methyl cellulose and sodium carboxymethylcellulose, alginicacids and salts thereof, polyethylene glycol, guar gum, polysaccharide,bentonites, sugars, invert sugars, poloxamers (PLURONIC™ F68, PLURONIC™F127), collagen, albumin, gelatin, cellulosics in non-aqueous solvents,combinations thereof and others known to those of ordinary skill in theart. Other binders include, for example, polypropylene glycol,polyoxyethylene-polypropylene copolymer, polyethylene ester,polyethylene sorbitan ester, polyethylene oxide, combinations thereofand other materials known to one of ordinary skill in the art.

As used herein, a conventional preservative is a compound used to atleast reduce the rate at which bioburden increases, but maintainsbioburden steady or reduces bioburden after contamination. Suchcompounds include, by way of example and without limitation,benzalkonium chloride, benzethonium chloride, benzoic acid, benzylalcohol, cetylpyridinium chloride, chlorobutanol, phenol, phenylethylalcohol, phenylmercuric nitrate, phenylmercuric acetate, thimerosal,metacresol, myristylgamma picolinium chloride, potassium benzoate,potassium sorbate, sodium benzoate, sodium propionate, sorbic acid,thymol, and methyl, ethyl, propyl or butyl parabens and others known tothose of ordinary skill in the art. It is understood that somepreservatives can interact with the alkylated cyclodextrin thus reducingthe preservative effectiveness. Nevertheless, by adjusting the choice ofpreservative and the concentrations of preservative and the alkylatedcyclodextrin adequately preserved formulations can be found.

As used herein, the term “diluent” or “filler” is intended to mean aninert substance used as a filler to create the desired bulk, flowproperties, and compression characteristics in the preparation of aliquid or solid dosage form. Such compounds include, by way of exampleand without limitation, a liquid vehicle (e.g., water, alcohol,solvents, and the like), dibasic calcium phosphate, kaolin, lactose,dextrose, magnesium carbonate, sucrose, mannitol, microcrystallinecellulose, powdered cellulose, precipitated calcium carbonate, sorbitol,and starch and other materials known to one of ordinary skill in theart.

As used herein, the term “direct compression excipient” is intended tomean a compound used in compressed solid dosage forms. Such compoundsinclude, by way of example and without limitation, dibasic calciumphosphate, and other materials known to one of ordinary skill in theart.

As used herein, the term “antioxidant” is intended to mean an agent thatinhibits oxidation and thus is used to prevent the deterioration ofpreparations by the oxidative process. Such compounds include, by way ofexample and without limitation, acetone, potassium metabisulfite,potassium sulfite, ascorbic acid, ascorbyl palmitate, citric acid,butylated hydroxyanisole, butylated hydroxytoluene, hypophosphorousacid, monothioglycerol, propyl gallate, sodium ascorbate, sodiumcitrate, sodium sulfide, sodium sulfite, sodium bisulfate, sodiumformaldehyde sulfoxylate, thioglycolic acid, EDTA, pentetate, and sodiummetabisulfite and others known to those of ordinary skill in the art.

As used herein, the term “buffering agent” is intended to mean acompound used to resist change in pH upon dilution or addition of acidor alkali. Such compounds include, by way of example and withoutlimitation, acetic acid, sodium acetate, adipic acid, benzoic acid,sodium benzoate, boric acid, sodium borate, citric acid, glycine, maleicacid, monobasic sodium phosphate, dibasic sodium phosphate,4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, lactic acid,tartaric acid, potassium metaphosphate, potassium phosphate, monobasicsodium acetate, sodium bicarbonate, tris, sodium tartrate and sodiumcitrate anhydrous and dihydrate and others known to those of ordinaryskill in the art.

A complexation-enhancing agent can be added to a formulation of theinvention. When such an agent is present, the ratio ofcyclodextrin/active agent can be changed. A complexation-enhancing agentis a compound, or compounds, that enhance(s) the complexation of theactive agent with the cyclodextrin. Suitable complexation enhancingagents include one or more pharmacologically inert water-solublepolymers, hydroxy acids, and other organic compounds typically used inpreserved formulations to enhance the complexation of a particular agentwith cyclodextrins.

Hydrophilic polymers can be used as complexation-enhancing,solubility-enhancing and/or water activity reducing agents to improvethe performance of formulations containing a CD-based preservative.Loftsson has disclosed a number of polymers suitable for combined usewith a cyclodextrin (underivatized or derivatized) to enhance theperformance and/or properties of the cyclodextrin. Suitable polymers aredisclosed in Pharmazie 56:746 (2001); Int. J. Pharm. 212:29 (2001);Cyclodextrin: From Basic Research to Market, 10th Int'l CyclodextrinSymposium, Ann Arbor, Mich., US, May 21-24, p. 10-15 (2000); PCT Int'lPub. No. WO 99/42111; Pharmazie 53:733 (1998); Pharm. Technol. Eur. 9:26(1997); J. Pharm. Sci. 85:1017 (1996); European Patent Appl. No. 0 579435; Proc. of the 9th Int'l Symposium on Cyclodextrins, Santiago deComostela, E S, May 31-Jun. 3, 1998, pp. 261-264 (1999); S.T.P. PharmaSciences 9:237 (1999); Amer. Chem. Soc. Symposium Series 737(Polysaccharide Applications):24-45 (1999); Pharma. Res. 15:1696 (1998);Drug Dev. Ind. Pharm. 24:365 (1998); Int. J. Pharm. 163:115 (1998); Bookof Abstracts, 216th Amer. Chem. Soc. Nat'l Meeting, Boston, Aug. 23-27CELL-016 (1998); J. Controlled Release 44:95 (1997); Pharm. Res. (1997)14(11), 5203; Invest. Ophthalmol. Vis. Sci. 37:1199 (1996); Proc. of the23rd Int'l Symposium on Controlled Release of Bioactive Materials453-454 (1996); Drug Dev. Ind. Pharm. 22:401 (1996); Proc. of the 8thInt'l Symposium on Cyclodextrins, Budapest, HU, Mar. 31-Apr. 2, 1996,pp. 373-376 (1996); Pharma. Sci. 2:277 (1996); Eur. J. Pharm. Sci.4S:S144 (1996); 3rd Eur. Congress of Pharma. Sci. Edinburgh, Scotland,UK Sep. 15-17, 1996; Pharmazie 51:39 (1996); Eur. J. Pharm. Sci. 4S:S143(1996); U.S. Pat. Nos. 5,472,954 and 5,324,718; Int. J. Pharm. 126:73(1995); Abstracts of Papers of the Amer. Chem. Soc. 209:33-CELL (1995);Eur. J. Pharm. Sci. 2:297 (1994); Pharm. Res. 11:S225 (1994); Int. J.Pharm. 104:181 (1994); and Int. J. Pharm. 110:169 (1994), the entiredisclosures of which are hereby incorporated by reference in theirentirety.

Other suitable polymers are well-known excipients commonly used in thefield of pharmaceutical formulations and are included in, for example,Remington's Pharmaceutical Sciences, 18th ed., pp. 291-294, A.R. Gennaro(editor), Mack Publishing Co., Easton, Pa. (1990); A. Martin et al.,Physical Pharmacy. Physical Chemical Principles in PharmaceuticalSciences, 3d ed., pp. 592-638 (Lea & Febinger, Philadelphia, Pa. (1983);A. T. Florence et al., Physicochemical Principles of Pharmacy, 2d ed.,pp. 281-334, MacMillan Press, London, UK (1988), the disclosures ofwhich are incorporated herein by reference in their entirety. Stillother suitable polymers include water-soluble natural polymers,water-soluble semi-synthetic polymers (such as the water-solublederivatives of cellulose) and water-soluble synthetic polymers. Thenatural polymers include polysaccharides such as inulin, pectin, alginderivatives (e.g. sodium alginate) and agar, and polypeptides such ascasein and gelatin. The semi-synthetic polymers include cellulosederivatives such as methylcellulose, hydroxyethylcellulose,hydroxypropylcellulose, their mixed ethers such ashydroxypropylmethylcellulose and other mixed ethers such ashydroxyethyl-ethylcellulose and hydroxypropylethylcellulose,hydroxypropylmethylcellulose phthalate and carboxymethylcellulose andits salts, especially sodium carboxymethylcellulose. The syntheticpolymers include polyoxyethylene derivatives (polyethylene glycols) andpolyvinyl derivatives (polyvinyl alcohol, polyvinylpyrrolidone andpolystyrene sulfonate) and various copolymers of acrylic acid (e.g.carbomer). Other natural, semi-synthetic and synthetic polymers notnamed here which meet the criteria of water solubility, pharmaceuticalacceptability and pharmacological inactivity are likewise considered tobe within the ambit of the present invention.

As used herein, a fragrance is a relatively volatile substance orcombination of substances that produces a detectable aroma, odor orscent. Exemplary fragrances include those generally accepted as safe bythe U.S. Food and Drug Administration.

As used herein, the term “glidant” is intended to mean an agent used insolid dosage formulations to promote flowability of the solid mass. Suchcompounds include, by way of example and without limitation, colloidalsilica, cornstarch, talc, calcium silicate, magnesium silicate,colloidal silicon, tribasic calcium phosphate, silicon hydrogel andother materials known to one of ordinary skill in the art.

As used herein, the term “lubricant” is intended to mean a substanceused in solid dosage formulations to reduce friction during compression.Such compounds include, by way of example and without limitation,calcium stearate, magnesium stearate, polyethylene glycol, talc, mineraloil, stearic acid, and zinc stearate and other materials known to one ofordinary skill in the art.

As used herein, the term “opaquant” is intended to mean a compound usedto render a coating opaque. An opaquant can be used alone or incombination with a colorant. Such compounds include, by way of exampleand without limitation, titanium dioxide, talc and other materials knownto one of ordinary skill in the art.

As used herein, the term “polishing agent” is intended to mean acompound used to impart an attractive sheen to solid dosage forms. Suchcompounds include, by way of example and without limitation, carnaubawax, white wax and other materials known to one of ordinary skill in theart.

As used herein, the term “disintegrant” is intended to mean a compoundused in solid dosage forms to promote the disruption of the solid massinto smaller particles which are more readily dispersed or dissolved.Exemplary disintegrants include, by way of example and withoutlimitation, starches such as corn starch, potato starch, pre-gelatinizedand modified starches thereof, sweeteners, clays, bentonite,microcrystalline cellulose (e.g., AVICEL®), carboxymethylcellulosecalcium, croscarmellose sodium, alginic acid, sodium alginate, cellulosepolacrilin potassium (e.g., AMBERLITE®), alginates, sodium starchglycolate, gums, agar, guar, locust bean, karaya, pectin, tragacanth,crospovidone and other materials known to one of ordinary skill in theart.

As used herein, the term “stabilizer” is intended to mean a compoundused to stabilize the therapeutic agent against physical, chemical, orbiochemical process which would reduce the therapeutic activity of theagent. Suitable stabilizers include, by way of example and withoutlimitation, albumin, sialic acid, creatinine, glycine and other aminoacids, niacinamide, sodium acetyltryptophonate, zinc oxide, sucrose,glucose, lactose, sorbitol, mannitol, glycerol, polyethylene glycols,sodium caprylate and sodium saccharin and other known to those ofordinary skill in the art.

As used herein, the term “tonicity modifier” is intended to mean acompound or compounds that can be used to adjust the tonicity of theliquid formulation. Suitable tonicity modifiers include glycerin,lactose, mannitol, dextrose, sodium chloride, sodium sulfate, sorbitol,trehalose and others known to those of ordinary skill in the art. Insome embodiments, the tonicity of the liquid formulation approximatesthe tonicity of blood or plasma.

As used herein, the term “antifoaming agent” is intended to mean acompound or compounds that prevents or reduces the amount of foamingthat forms on the surface of the liquid formulation. Suitableantifoaming agents include dimethicone, simethicone, octoxynol andothers known to those of ordinary skill in the art.

As used herein, the term “bulking agent” is intended to mean a compoundused to add bulk to the solid product and/or assist in the control ofthe properties of the formulation during lyophilization. Such compoundsinclude, by way of example and without limitation, dextran, trehalose,sucrose, polyvinylpyrrolidone, lactose, inositol, sorbitol,dimethylsulfoxide, glycerol, albumin, calcium lactobionate, and othersknown to those of ordinary skill in the art.

As used herein, the term “cryoprotectant” is intended to mean a compoundused to protect an active therapeutic agent from physical or chemicaldegradation during lyophilization. Such compounds include, by way ofexample and without limitation, dimethyl sulfoxide, glycerol, trehalose,propylene glycol, polyethylene glycol, and others known to those ofordinary skill in the art.

As used herein, the term “emulsifier” or “emulsifying agent” is intendedto mean a compound added to one or more of the phase components of anemulsion for the purpose of stabilizing the droplets of the internalphase within the external phase. Such compounds include, by way ofexample and without limitation, lecithin,polyoxylethylene-polyoxypropylene ethers, polyoxylethylene-sorbitanmonolaurate, polysorbates, sorbitan esters, stearyl alcohol, tyloxapol,tragacanth, xanthan gum, acacia, agar, alginic acid, sodium alginate,bentonite, carbomer, sodium carboxymethylcellulose, cholesterol,gelatin, hydroxyethyl cellulose, hydroxypropyl cellulose, octoxynol,oleyl alcohol, polyvinyl alcohol, povidone, propylene glycolmonostearate, sodium lauryl sulfate, and others known to those ofordinary skill in the art.

A solubility-enhancing agent can be added to the formulation of theinvention. A solubility-enhancing agent is a compound, or compounds,that enhance(s) the solubility of the active agent when in a liquidformulation. When such an agent is present, the ratio ofcyclodextrin/active agent can be changed. Suitable solubility enhancingagents include one or more organic solvents, detergents, soaps,surfactant and other organic compounds typically used in parenteralformulations to enhance the solubility of a particular agent.

Suitable organic solvents include, for example, ethanol, glycerin,polyethylene glycols, propylene glycol, poloxomers, and others known tothose of ordinary skill in the art.

Formulations comprising the alkylated cyclodextrin composition of theinvention can include oils (e.g., fixed oils, peanut oil, sesame oil,cottonseed oil, corn oil olive oil, and the like), fatty acids (e.g.,oleic acid, stearic acid, isostearic acid, and the like), fatty acidesters (e.g., ethyl oleate, isopropyl myristate, and the like), fattyacid glycerides, acetylated fatty acid glycerides, and combinationsthereof. Formulations comprising the alkylated cyclodextrin compositionof the invention can also include alcohols (e.g., ethanol, iso-propanol,hexadecyl alcohol, glycerol, propylene glycol, and the like), glycerolketals (e.g., 2,2-dimethyl-1,3-dioxolane-4-methanol, and the like),ethers (e.g., poly(ethylene glycol) 450, and the like), petroleumhydrocarbons (e.g., mineral oil, petrolatum, and the like), water,surfactants, suspending agents, emulsifying agents, and combinationsthereof.

It should be understood, that compounds used in the art ofpharmaceutical formulations generally serve a variety of functions orpurposes. Thus, if a compound named herein is mentioned only once or isused to define more than one term herein, its purpose or function shouldnot be construed as being limited solely to that named purpose(s) orfunction(s).

Formulations comprising the alkylated cyclodextrin composition of theinvention can also include biological salt(s), sodium chloride,potassium chloride, and other electrolyte(s).

Since some active agents are subject to oxidative degradation, a liquidformulation according to the invention can be substantially oxygen-free.For example, the headspace of a container containing a liquidformulation can made oxygen-free, substantially oxygen-free, oroxygen-reduced by purging the headspace with an inert gas (e.g.,nitrogen, argon, carbon dioxide, and the like), or by bubbling an inertgas through a liquid formulation. For long-term storage, a liquidformulation containing an active agent subject to oxidative degradationcan be stored in an oxygen-free or oxygen-reduced environment. Removalof oxygen from the formulation will enhance preservation of theformulation against aerobic microbes; whereas, addition of oxygen to theformulation will enhance preservation against anaerobic microbes.

The phrase “pharmaceutically acceptable” is employed herein to refer tothose compounds, materials, compositions, and/or dosage forms which are,within the scope of sound medical judgment, suitable for use in contactwith the tissues of human beings and animals without excessive toxicity,irritation, allergic response, or other problem or complication,commensurate with a reasonable benefit/risk ratio.

As used herein, the term “patient” or “subject” are taken to mean warmblooded animals such as mammals, for example, cats, dogs, mice, guineapigs, horses, bovine cows, sheep, non-humans, and humans.

A formulation of the invention will comprise an active agent present inan effective amount. By the term “effective amount,” is meant the amountor quantity of active agent that is sufficient to elicit the required ordesired response, or in other words, the amount that is sufficient toelicit an appreciable biological response when administered to asubject.

The compositions of the present invention can be present in formulationsfor dosage forms such as a reconstitutable solid, tablet, capsule, pill,troche, patch, osmotic device, stick, suppository, implant, gum,effervescent composition, injectable liquid, ophthalmic or nasalsolutions, or inhalable powders or solutions.

The invention also provides methods of preparing a liquid formulationcomprising one or more active agents and an alkylated cyclodextrincomposition, wherein the alkylated cyclodextrin composition comprises analkylated cyclodextrin and less than 500 ppm of a phosphate. A firstmethod comprises: forming a first aqueous solution comprising analkylated cyclodextrin composition; forming a second solution orsuspension comprising one or more active agents; and mixing the firstand second solutions to form a liquid formulation. A similar secondmethod comprises adding one or more active agents directly to a firstsolution without formation of the second solution. A third methodcomprises adding an alkylated cyclodextrin composition directly to the asolution/suspension containing one or more active agents. A fourthmethod comprises adding a solution comprising one or more active agentsto a powdered or particulate alkylated cyclodextrin composition. A fifthmethod comprises adding one or more active agents directly to a powderedor particulate alkylated cyclodextrin composition, and adding theresulting mixture to a second solution. A sixth method comprisescreating a liquid formulation by any of the above methods and thenisolating a solid material by lyophilization, spray-drying, asepticspray drying, spray-freeze-drying, antisolvent precipitation, a processutilizing a supercritical or near supercritical fluid, or another methodknown to those of ordinary skill in the art to make a powder forreconstitution.

Specific embodiments of the methods of preparing a liquid formulationinclude those wherein: 1) the method further comprises sterile filteringthe formulation using a filtration medium having a pore size of 0.1 umor larger; 2) the liquid formulation is sterilized by irradiation orautoclaving; 3) the method further comprises isolating a solid from thesolution; 4) the solution is purged with nitrogen or argon or otherinert pharmaceutically acceptable gas such that a substantial portion ofthe oxygen dissolved in, and/or in surface contact with, the solution isremoved.

The invention also provides a reconstitutable solid pharmaceuticalcomposition comprising one or more active agents, an alkylatedcyclodextrin composition and optionally at least one otherpharmaceutical excipient. When this composition is reconstituted with anaqueous liquid to form a preserved liquid formulation, it can beadministered by injection, infusion, topically, by inhalation or orallyto a subject.

Some embodiments of the reconstitutable solid pharmaceutical compositionincludes those wherein: 1) the pharmaceutical composition comprises anadmixture of an alkylated cyclodextrin composition and a solidcomprising one or more active agents and optionally at least one solidpharmaceutical excipient, such that a major portion of the active agentis not complexed with an alkylated cyclodextrin prior to reconstitution;and/or 2) the composition comprises a solid mixture of an alkylatedcyclodextrin composition and one or more active agents, wherein a majorportion of the one or more active agents is complexed with the alkylatedcyclodextrin prior to reconstitution.

A composition of the invention can be used in a pharmaceutical dosageform, pharmaceutical composition or other such combination of materials.These alkylated cyclodextrin compositions are also useful as, but notlimited to, analytical reagents, food and cosmetics adjuvants and/oradditives, and as environmental clean-up agents.

In view of the above description and the examples below, one of ordinaryskill in the art will be able to practice the invention as claimedwithout undue experimentation. The foregoing will be better understoodwith reference to the following examples that detail certain proceduresfor the preparation of molecules, compositions, and formulationsaccording to the present invention. All references made to theseexamples are for the purposes of illustration. The following examplesshould not be considered exhaustive, but merely illustrative of only afew of the many embodiments contemplated by the present invention.

EXAMPLES Example 1 Determination of Active Agent Solubility

Comparative evaluation of the solubilization effect of varioussulfoalkyl ether cyclodextrin compositions on pharmaceutical activeagents was determined as follows. A 0.04 M stock solutions of eachselected cyclodextrin was prepared with purified water. Clarity ofsolutions was determined by visual inspection or instrumentally. A clearsolution is at least clear by visual inspection with the unaided eye.Each pharmaceutical active agent, tested in duplicate, was combined with2 mL or 4 mL of a SAE-CD aqueous solution.

Pharmaceutical active agents were weighed in amounts in excess of theiranticipated solubility, and placed in TEFLON®-lined screw-capped vials.The active agents were present in amounts of at least 3 mg/mL. Each vialwas then filled with the appropriate amount of cyclodextrin solution(either 2 mL or 4 mL). The vials were vortexed and sonicated to aid inwetting the solids with the fluid. The vials were then placed on a labquake or a roller mixer for equilibration. The vials were visuallyinspected periodically to assure that the solids were adequately beingwetted and in contact with the fluid. The fluid within the vials wasthen sampled periodically to determine the concentration of thepharmaceutical active agent present in solution. Samples were typicallymeasured at 24 hour intervals.

Sampling of the vials to determine active agent solubility was performedby decanting 1 mL of solution from the vial followed by optionalcentrifuging. The removed supernatant was then filtered using a 0.22 μmsyringe filter, and diluted with the mobile phase to an appropriateconcentration within the standard curve. The samples were then analyzedby HPLC to determine concentration of the solubilized drug derivatives.

Example 2 Determination of Moisture Content

The following procedure was used to evaluate the moisture content of thealkylated cyclodextrins. Determinations were performed in duplicate on250 mg of each using a Brinkman Karl-Fischer Coulometer (BrinkmanInstruments Co., IL). A known weight of solid cyclodextrin was added tothe Karl-Fischer Coulometer and the total amount of water in the sampleis measured. The total amount of water present is then converted to apercentage of the solid to give the percent moisture content of thesample.

Example 3 Analysis by Capillary Electrophoresis

The following procedure was used to analyze the SAE-CD derivativecompositions by capillary electrophoresis. A Beckman P/ACE 2210capillary electrophoresis system coupled with a UV absorbance detector(Beckman Instruments, Inc., Fullereton, Calif.) was used to analyzesolutions of SBE-β-CD and SBE-γ-CD derivatives. The separations wereperformed at 25° C. using a fused silica capillary (having a 50 μm innerdiameter, a total length of 57 cm, and an effective length of 50 cm)with a pH adjusted running buffer of 30 mM benzoic acid and 100 mM TRIS(tris-hydroxymethyl-aminomethanol).

The capillary was treated with the following wash sequence before eachinjection: water, 0.01 N NaOH, and running buffer. The detector was setat 214 nm. The voltage was 30 kV. Samples were introduced by pressureinjections: 20 seconds at 0.5 psi.

Example 4

An α-CD derivative composition having a monomodal distribution profilecan be prepared according to Example 5 or any of the literature methodscited herein, except that α-CD would be used in place of the β-CD orγ-CD. An exemplary SBE-α-CD is made using the following procedure,wherein an α-cyclodextrin in an alkaline aqueous medium is derivatizedwith an SBE precursor to form the SBE-α-CD. The α-CD is dissolved inNaOH aqueous solution, heated to 70° C., and stirred until completedissolution. Once dissolution is complete the reaction temperature isincreased to between 70° C. to 75° C. Then, 1,4-butanesultone was addedover a period of at least 30 minutes. The pH is monitored during thefirst 4 hours and the reaction is allowed to continue at 70° C. for atleast an additional 16 hours. The reaction mixture is cooled and dilutedwith water (roughly one third the total reaction volume). The solutionis further treated with carbon (0.07 gram of carbon/gram ofcyclodextrin), neutralized with HCl to pH 6-6.5 and filtered through a0.45 μm filter. The solution is purified by ultrafiltration using a 650MWCO membrane. The ultrafiltration end point is determined by capillaryelectrophoresis wherein the filtrate showed no or substantially nopresence of 4-hydroxybutane-1-sulfonic acid and/or disodiumbis(4-sulfobutyl)ether, and by osmolarity, wherein the permeate sampleshad little to no ion present. The solution is filtered through a 0.22 μmfilter and neutralized (pH 6-6.5). The resulting solution isconcentrated to roughly a 50% solution by rotary evaporation at between50° C. to 60° C. under less than 30 mmHg vacuum. The solution isfreeze-dried to yield a SBE-α-CD white solid.

Example 5 SBE_(6.6)-β-CD Synthesis

A SBE_(6.6)-β-CD composition was synthesized according to the followingprocedure, in which a β-cyclodextrin in an alkaline aqueous medium wasderivatized with an SBE precursor to form the SBE_(6.6)-β-CD. An aqueoussolution of sodium hydroxide was prepared by charging 61.8 kg of sodiumhydroxide to 433 kg of water for a 12.5% w/w solution. The reactorcontents were heated to between 40° C. to 50° C. before beginning theaddition of 270 kg of β-CD over 30 to 60 minutes. The reactiontemperature was adjusted to between 65° C. to 95° C. before the additionof 259 kg of 1,4-butane sultone over 30 to 60 minutes. Over the next 6hours the pH of the solution was maintained above 9 using an aqueoussolution of sodium hydroxide. Following the reaction an additional 13.5kg of sodium hydroxide as a 20% solution was charged to the reaction.The contents were maintained at between 70° C. to 80° C. until theresidual level of 1,4-butane sultone was sufficiently low. The contentswere cooled to less than 30° C. and the reaction solution was adjustedto pH 6.5-7.5 with aqueous solution of hydrochloric acid. This processyielded 350 to 450 kg of SAE-CD.

Example 6 SBE_(6.6)-β-CD Diafiltration and Ultrafiltration

The SBE_(6.6)-β-CD of Example 5 was purified by the following procedure.The reaction solution was diluted with 800 kg of water. The solution wastransferred and further diluted with 500 kg of water. Diafiltration wasinitiated using a Millipore Helicon Automated Ultrafiltration Systemusing 1000 MWCO spiral wound regenerated cellulose membranes having atleast 750 ft² of membrane area and maintaining a constant solutionvolume (±1%) until a sample of the returnate has 25 ppm or less ofsodium chloride. The solution was concentrated by ultrafiltration untilan appropriate solution mass was achieved.

Example 7 SBE_(6.6)-β-CD Carbon Processing of the Present Invention

Following the diafiltration and ultrafiltration in Example 6, theSBE_(6.6)-β-CD was carbon purified by the following procedure. A columnwas charged with 32 kg (about 11-12% wt. (11.8-12% wt.) of the startingamount of β-cyclodextrin) of SHIRASAGI®DC32 granular activated carbonand washed thoroughly with water until the wash samples have a constantconductivity. The ratio of SBE_(6.6)-β-CD to activated carbon was about8.4:1 to 8.5:1 (about 8.44:1). Once washed, the reaction solution waspassed (recycled) through the carbon for at least 2 hours to complete afirst treatment cycle.

A second column was charged with 32 kg (about 11-12% wt. of the startingamount of β-cyclodextrin) of SHIRASAGI® DC32 granular activated carbonand washed thoroughly with water until the wash samples have a constantconductivity. Once washed, the reaction solution was passed through thecarbon for at least 2 hours to complete a second treatment cycle.

Example 8 SBE_(6.6)-β-CD Concentration and Isolation

The carbon-treated SBE_(6.6)-β-CD solutions prepared in Example 7 wereconcentrated and isolated using the following procedure: aSBE_(6.6)-β-CD solution was filtered through 0.65 μm and 0.22 μm filtersand then concentrated at a reduced pressure of −0.6 bar to −0.7 bar at atemperature of 65° C. to 72° C., with agitation at 70 rpm to 100 rpm,until a solution having a SBE_(6.6)-β-CD concentration of 50% w/w wasachieved. The concentrated solution was cooled to below 60° C., and thenfiltered through 0.65 μm and 0.22 μm filters. The filtered solution wasthen spray dried using a fluidized spray dryer (“FSD”) system at aninlet temperature of 170° C., an initial pressure of 20 bar, andchambers 1-3 having set points of 125° C., 105° C., and 100° C.,respectively.

Example 9 Determination of Cyclodextrin Substitution Pattern by ¹H-NMR,¹³C-NMR, COSY-NMR and HMQC on a Bruker AVANCE® 400 or 500 Instrument inD₂O Solutions

Determination of the substitution pattern is conducted according to themethod of Example 6 of WO 2005/042584, the relevant disclosures of whichare hereby incorporated by reference.

Example 10 SBE₆₆-O-CD Comparative Carbon Processing

An exemplary SBE_(6.6)-β-CD was carbon purified by the followingprocedure: a column was charged with 32 kg (about 11-12% wt. (11.8-12%wt.) of the starting amount of β-cyclodextrin in Example 5) ofSHIRASAGI® DC32 granular activated carbon and washed thoroughly withwater until the wash samples have a constant conductivity. Once washedthe reaction solution was passed through the carbon for at least 2hours.

Example 11 SBE_(6.6)-β-CD Impurity Analysis I

SBE_(6.6)-β-CD samples treated either once or twice with activatedcarbon according to Examples 10 and 7, respectively, concentrated andisolated by the process described in Example 8, were then analyzed byUV/vis spectrophotometry. The analysis was performed by dissolving anappropriate amount of SBE_(6.6)-β-CD in water (e.g., 0.1 g to 6 g ofSBE_(6.6)-β-CD, corrected for water content, dissolved in 10 mL ofwater) to provide solutions containing from 1% to 60% w/w of thederivatized cyclodextrin.

The carbon-treated cyclodextrin solutions were analyzed on a PerkinElmer Lambda 35 UV/Vis spectrophotometer, scanning from 190 nm to 400 nmat a speed of 240 nm/min and a slit width of 1.0 nm. The samples wereblanked against water before analysis. The UV/vis absorption spectra ofvarious concentrations of SBE_(6.6)-β-CD solutions after one and twoactivated carbon treatments is provided graphically in FIGS. 1 and 2,respectively, which provide a graphic representation of theSBE_(6.6)-β-CD lots after one or two carbon treatments analyzed by theUV method. Referring to FIG. 1, the data shows that a higherconcentration of impurities having an absorption in the UV/visibleregion of the spectrum is present when an SBE_(6.6)-β-CD solution istreated only once with activated carbon. Referring to FIG. 2, the datashow that a second carbon treatment reduces the level of UV/visabsorbing impurities at least five fold or more.

Example 12 SBE_(6.6)-β-CD Impurity Analysis II

An exemplary SBE_(6.6)-β-CD sample was analyzed by UV/Visspectrophotometry using the following procedure: a 50% w/wSBE_(6.6)-β-CD solution was prepared by dissolving 54.1 grams ofSBE_(6.6)-β-CD, corrected for water content, in a caustic solution of12.5 grams of sodium hydroxide in 100 mL of water. The initial solutionwas analyzed on a PERKIN ELMER Lambda 35 UV/Vis spectrophotometer,scanning from 190 nm to 400 nm at a speed of 240 nm/min and a slit widthof 1.0 nm. The sample was blanked against water before analysis. Thesolution was placed in a 60° C. oven for up to 168 hours. Solutionsamples were analyzed at 24 hours, 72 hours, 96 hours, and 168 hours.

FIG. 3 provides a graphical representation of the results from thethermal and caustic stress on the SBE_(6.6)-β-CD compositions. Referringto FIG. 3, the data shows that within 24 hours, a significant absorptionat a wavelength of 245 nm to 270 nm has formed, and that this absorptionincreases with the duration of thermal and caustic exposure. By 168hours (7 days), the absorption maximum at a wavelength of 245 nm to 270nm has increased to an equal magnitude with the absorption having amaximum at about 230 nm. Also of note is that the absorption at awavelength of 320 nm to 350 nm also increases with time of exposure. Thedata shows that a drug-degrading impurity having an absorption at awavelength of 245 nm to 270 nm, as well as a color forming agent havingan absorption at a wavelength of 320 nm to 350 nm, increase inconcentration over time under exposure to heat and/or causticconditions.

Example 13 Measurements of Color-Forming Agents

SBE_(6.6)-β-CD compositions that underwent single- or double-treatmentwith activated carbon (according to Examples 10 and 7, respectively)were formulated with a triazole antifungal API (posaconazole, which waspurchased from Schering-Plough as an aqueous oral suspension, NOXAFIL®).The formulation procedure is provided below.

Aqueous solution samples of a triazole antifungal API (5 mg/mL) and aSBE_(6.6)-β-CD composition (100 mM, pH 3) were prepared usingSBE_(6.6)-β-CD Lot Nos. 17CX01.HQ00044, 17CX01.HQ00037, 17CX01.HQ00035,17CX01.HQ00033, and 17CX01.HQ00029. All solution samples were filteredthrough 0.22 um PVDF filter, and separated into vials. The UV/Visabsorption of a portion of the initial solutions was measured using a 1cm Hunter cuvette on a PERKIN ELMER Lambda 35 UV/Vis spectrophotometer,scanning from 190 nm to 400 nm at a speed of 240 nm/min and a slit widthof 1.0 nm, and analyzed on a Hunter Labs ULTRASCAN® colorimeter usingHunter Labs universal software, version 4.10. The samples were blankedagainst water before measurement. The remaining portions of samples werethen placed into a 60° C. oven for 7 days and then reanalyzed for colorchanges using the same procedure. The data is shown in the followingtables.

SBE_(6.6)-β-CD Initial Solutions: UV/Vis Analysis 30% SBE_(6.6)- UVanalysis β-CD Solutions Carbon (Max Abs @ Lot No. Processing Condition λ= 245-270 nm) 17CX01.HQ00044 2 Granular carbon treatments 0.05(SHIRASAGI ® DC-32) 17CX01.HQ00037 2 Granular carbon treatments 0.11(SHIRASAGI ® DC-32) 17CX01.HQ00035 2 Granular carbon treatments 0.16(SHIRASAGI ® DC-32) 17CX01.HQ00033 1 Granular carbon treatments 0.25(SHIRASAGI ® DC-32) 17CX01.HQ00029 1 Granular carbon treatments 0.32(SHIRASAGI ® DC-32)

SBE_(6.6)-β-CD Solution Color Analysis t = 7 days @ SBE_(6.6)-β-CD t = 060° C. (100 mM) Carbon Processing Cond. (DE) (DE) 17CX01.HQ00044 2Granular carbon treatments 0.08 0.01 (SHIRASAGI ® DC-32) 17CX01.HQ000372 Granular carbon treatments 0.12 0.15 (SHIRASAGI ® DC-32)17CX01.HQ00035 2 Granular carbon treatments 0.09 0.18 (SHIRASAGI ®DC-32) 17CX01.HQ00033 1 Granular carbon treatments 0.2 0.41 (SHIRASAGI ®DC-32) 17CX01.HQ00029 1 Granular carbon treatments 0.12 0.38(SHIRASAGI ® DC-32) L = lightness; 100 for perfect white and 0 forblack; a = measures redness when positive, grey when zero, and greennesswhen negative; b = measures yellowness when positive, grey when zero,and blueness when negative; DE = Total Differences √(ΔL² + Δa² + Δb²)from the Standard

Triazole API/SBE_(6.6)-β-CD Solution Color Analysis UV/Vis Analysis (DE)Formulation t = 0 (DE) t = 7 days @ 60° C. (DE) 17CX01.HQ00044 0.46 4.3717CX01.HQ00037 0.2 3.76 17CX01.HQ00035 0.24 4.43 17CX01.HQ00033 0.45 517CX01.HQ00029 0.36 6.26 L = lightness; 100 for perfect white and 0 forblack; a = measures redness when positive, grey when zero, and greennesswhen negative; b = measures yellowness when positive, grey when zero,and blueness when negative; DE = Total Differences √(ΔL² + Δa² + Δb²)from the Standard.

The UV analysis demonstrated that the UV-active impurities present inthe initial SBE_(6.6)-β-CD composition are much lower when thecyclodextrin composition is treated twice with activated carbon. TheHunter color analysis of the SBE_(6.6)-β-CD composition indicated lowerDE values for those SBE_(6.6)-β-CD lots that were processed using adouble activated carbon treatment. Thus, the lower impurity levels inthe SBE_(6.6)-β-CD composition that was treated twice with activatedcarbon resulted in reduced formation of color-forming agents.

Example 14 SBE_(6.6)-β-CD DS Subjected to Heat then Carbon Treatment

The effect of heating a derivatized cyclodextrin composition of thepresent invention was studied as follows. The SBE_(6.6)-β-CD compositionprepared according to Example 5 was dissolved in aqueous solution andanalyzed using UV/vis spectrophotometry. Specifically, a 30% w/wβ-cyclodextrin solution was prepared by dissolving 70 grams ofSBE_(6.6)-β-CD Lot No. 17CX01.HQ00044 (corrected for water content) in230 mL of water. This initial solution was analyzed on a PERKIN ELIMERLambda 35 UV/Vis spectrophotometer, scanning from 190 nm to 400 nm at aspeed of 240 nm/min and a slit width of 1.0 nm. The sample was blankedagainst water before analysis. The solution was heated with agitation to70° C. for 48 hours. The solution was cooled to ambient temperature anddivided. To each of the divided solutions, pre-washed SHIRASAGI® DC32granular activated carbon was added. The SBE_(6.6)-β-CD solutions werestirred for 3 hours, and then the activated carbon was filtered using a0.22 PVDF filter. The solutions were analyzed using a PERKIN ELMERLambda 35 UV/Vis spectrophotometer, scanning from 190 nm to 400 nm at aspeed of 240 nm/min and a slit width of 1.0 nm. The samples were blankedagainst water before analysis.

The data is depicted graphically in FIG. 4. Referring to FIG. 4, theUV/vis absorption of the solution prior to heat treatment (+ + + +),immediately after 48 hours of heat treatment (▪ ▪ ▪ ▪), and afterexposure to activated carbon at a loading of 0.24% w/w (• • • • • • • •)10% w/w (

) 25% w/w (♦ ♦ ♦ ♦), and 50% w/w (□ □ □ □), (according to theconcentration of SBE_(6.6)-β-CD), is provided. The data show thatexposing the SBE_(6.6)-β-CD solution to heat for 48 hours resulted in asignificant increase (approximately 95%) in the absorption maximum at awavelength of 245 nm to 270 nm. However, treatment with activated carbondecreases the absorption in this wavelength range. Thus, thedrug-degrading impurity having an absorption at a wavelength of 245 nmto 270 nm increases with heating, but can be removed through carbontreatment.

Example 15 SBE_(6.6)-β-CD DS and API Stability

Comparative evaluation of various lots of SBE_(6.6)-β-CD processed witha single or a double carbon treatment with an antipsychotic API(aripiprazole) were examined by UV/vis spectrophotometry and HPLCanalysis. The general procedure used to evaluate the stability of theSBE_(6.6)-β-CD/API formulations is provided below.

Aqueous solutions comprising samples of the API (aripiprazole) wereprepared with an API concentration of 7.5 mg/mL and a SBE_(6.6)-β-CDconcentration of 150 mg/mL. Tartaric acid was added to water untildissolved, and the SBE_(6.6)-β-CD was then added to the tartaric acidsolution. The API was then added to the solutions, and dissolved withinabout 10 minutes of the additions. The mixture was stirred about 1 hour,heated treated, and then filtered through a sterile filter. This processwas performed using the following lots of SBE_(6.6)-β-CD, some of whichunderwent a single treatment with activated carbon and others thatunderwent two treatments with activated carbon (SBE_(6.6)-β-CD Lot Nos.17CX01.HQ00021, 17CX01.HQ00025, 17CX01.HQ00029, 17CX01.HQ00035,17CX01.HQ00036, 17CX01.HQ00037, 17CX01.HQ00038, 17CX01.HQ00039,17CX01.HQ00040, 17CX01.HQ00041, 17CX01.HQ00042, 17CX01.HQ00043, and17CX01.HQ00044). Solution samples were placed in a stability chamber at50° C. for up to 9 weeks. Samples were removed at 4 weeks and again at 9weeks, and HPLC analysis was performed to determine the extent of APIdegradation.

Aqueous solution samples were analyzed by UV/vis spectrophotometry usingthe following procedure. A 30% w/w β-cyclodextrin solution was preparedby dissolving of the above SBE_(6.6)-β-CD lots (corrected for watercontent) in water. The solution was analyzed in a 1 cm cuvette using aPERKIN ELMER Lambda 35 UV/Vis spectrophotometer, scanning from 190 nm to400 nm at a speed of 240 nm/min and a slit width of 1.0 nm. The sampleswere blanked against water before analysis. The following tables includethe data from this study.

SBE_(6.6)-β-CD Lot Summary and UV Content 30% SBE_(6.6)-β-CD # of CarbonSAE-CD UV Analysis Solutions Lots Treatments (Max Abs @ λ = 245-270 nm)17CX01.HQ00021 1 0.21 17CX01.HQ00025 1 0.44 17CX01.HQ00029 1 0.2117CX01.HQ00035 2 0.16 17CX01.HQ00036 2 0.14 17CX01.HQ00037 2 0.1517CX01.HQ00038 2 0.1 17CX01.HQ00039 2 0.09 17CX01.HQ00040 2 0.0917CX01.HQ00041 2 0.08 17CX01.HQ00042 2 0.07 17CX01.HQ00043 2 0.117CX01.HQ00044 2 0.05

SAE-CD & API Impurity Analysis SBE_(6.6)-β-CD API Assay (150 mg/mL) t =4 wks Δ Assay t = 9 wks Δ Assay API (7.5 mg/mL) t = 0 @ 50° C. (t = 0→t= 4 wks) @ 50° C. (t = 0→t = 9 wks) 17CX01.HQ00021 0.05 0.90 0.85 1.241.19 17CX01.HQ00025 0.00 1.08 1.08 1.42 1.42 17CX01.HQ00029 0.23 1.040.81 1.52 1.29 17CX01.HQ00035 0.08 0.63 0.55 0.96 0.88 17CX01.HQ000360.08 0.58 0.50 0.87 0.79 17CX01.HQ00037 0.08 0.65 0.57 0.85 0.7717CX01.HQ00038 0.07 0.52 0.45 0.78 0.71 17CX01.HQ00039 0.07 0.55 0.480.86 0.79 17CX01.HQ00040 0.00 0.21 0.21 0.53 0.53 17CX01.HQ00041 0.000.27 0.27 0.51 0.51 17CX01.HQ00042 0.00 0.34 0.34 0.64 0.6417CX01.HQ00043 0.07 0.61 0.54 1.00 0.93 17CX01.HQ00044 0.00 0.13 0.130.35 0.35

The data show that the API undergoes significantly higher degradationwhen it is formulated with an SBE_(6.6)-β-CD lot that has undergone onlya single treatment with activated carbon. The API formulation thatcontained SBE_(6.6)-β-CD Lot No. 17CX01.HQ00025 had the highestUV-active impurity levels (Max. Abs.=0.44 A.U.) and the API underwent atotal degradation of 1.42% after 9 weeks. SBE_(6.6)-β-CD lots thatunderwent two treatments with activated carbon were measurably lower interms of both levels of UV-active impurities and the extent of APIdegradation. The extent of API degradation that occurred during storagefor 9 weeks at 50° C. correlated with the concentration of UV-activeimpurities present in the formulations. For example, the API formulationcontaining SBE_(6.6)-β-CD Lot No. 17CX01.HQ00044 (which containedUV-active impurities having a Max. Abs.=0.05 AU.) underwent a totaldegradation of only 0.35% after 9 weeks at 50° C.

FIG. 5 provides a graphical representation of the correlation betweenthe initial UV/vis absorption of the SBE_(6.6)-β-CD lots at a wavelengthof 245 nm to 270 nm, and the extent of API degradation determined at 4weeks and 9 weeks. Referring to FIG. 5, the data shows that at both 4weeks (

) and 9 weeks (

), the extent of the API degradation increases with the concentration ofthe UV/vis absorbing drug-degrading impurities present in theSBE_(6.6)-β-CD composition.

Example 16 Measurement of Impurities by Processing

The SBE_(6.6)-β-CD samples after reaction workup (Example 5), afterultrafiltration (Example 6), after the second carbon column (Example 7),after concentration (Example 8), and as a final product were separated,identified, and quantified using a Shimadzu Prominence 20A HPLCinstrument and a ZIC® pHILIC column (150×4.6 mm, 5 μm, 200 A, PEEK MerckSeQuant™ SN 1479) utilizing a Corona (ESA Bioscience) Charged AerosolDetector. A gradient mobile phase method is performed using a solutionof 100 mM ammonium formate (pH adjusted to 4.6), methanol, 2-propanol,and acetonitrile 15/5/20/65 (A) and a solution of 30 mM ammonium formate(pH adjusted to 4.6), methanol, 2-propanol, and acetonitrile 65/5/20/10(B). A sample solution of Captisol® is prepared at a concentration ofapproximately 40 mg/mL in HPLC grade acetonitrile/water and analyzedversus a prepared reference solution of known concentration of4-hydroxybutane-1-sulfonic acid, disodium bis(4-sulfobutyl)ether,chloride, sodium, phosphate, silicon dioxide, and β-cyclodextrin inacetonitrile/water at the impurity specification limit. Validationstudies have shown the method to be specific, linear in the impurityspecification range, precise, and stable. The gradient used is shown inthe following table.

Time (min) % B 0 20 15 35 28 90 32 90 36 15 38 20 45 20

As shown in FIG. 6, after ultrafiltration of the crude SBE_(6.6)-β-CDproduct, impurities such as β-cyclodextrin and4-hydroxybutane-1-sulfonic acid (4-HBSA) are present. After a secondcolumn with activated carbon, the amount of β-cyclodextrin and4-hydroxybutane-1-sulfonic acid impurities have been reduced. However,as shown in FIG. 6, there are high amounts of chloride present in theproduct after the two columns.

Example 17 Measurement of Chloride Concentration

The SBE_(6.6)-β-CD samples after reaction workup (Example 5), afterultrafiltration

(Example 6), after the second carbon column (Example 7), afterconcentration (Example 8), and as a final product were analyzed using aCorona (ESA Bioscience) Charged Aerosol Detector to determine chlorideconcentration.

As shown in FIG. 7, after the ultrafiltration, the residual level ofchloride drops to approximately zero. After further purification usingtwo columns of activated carbon, chloride is added back into theSBE_(6.6)-β-CD solution.

Example 18 Measurement of Chloride Concentration

The SBE_(6.6)-β-CD samples after reaction workup (Example 5), afterultrafiltration

(Example 6), 5, 10, and 20 minutes after addition to the first activatedcarbon column, and 5, 10, and 20 minutes after addition to the secondactivated carbon column were analyzed using a Corona (ESA Bioscience)Charged Aerosol Detector to determine chloride concentration.

As shown in FIG. 8, the chloride impurity level for two SBE_(6.6)-β-CDcommercial batches is approximately zero after the ultrafiltration andincreases substantially after treatment with activated carbon during thefirst 5 minutes, with the level dropping after 10 and 20 minutes.

Example 19 Purification of Activated Carbon Using a Dedicated TankSystem

The activated carbon can be added to a dedicated tank system with anagitator and screen system. The activated carbon can be charged followedby washing with several portions of water at a determined agitation ratefor a determined time period. Following the water wash, the water layercan be removed from the dedicated tank and washed with additional water.After additional water washes the conductivity of the eluted water canbe determined using ion chromatography (4.0×250 mm USP packing L50 orsimilar with mobile phases of 4 mM sodium bicarbonate in methanol/water(1:9), a flow rate of 1 mL/min, a sample volume of 20 μL, and a run timeof 10 min) and when the conductivity is below a predetermined level thecarbon can be suspended in water and pumped into carbon housings. Theactivated carbon would then be ready for addition of the alkylatedcyclodextrin solution.

Example 20 Purification of SBE_(6.6)-β-CD Using Activated Carbon Havinga Determined Conductivity Level

A column was charged with 32 kg (about 11-12% wt. (11.8-12% wt.) of thestarting amount of β-cyclodextrin) of SHIRASAGI® DC32 granular activatedcarbon and washed thoroughly with water until the wash samples had aconductivity level less than 10 μS as shown in the following Table.Conductivity was determined using ion chromatography (4.0×250 mm USPpacking L50 or similar with mobile phases of 4 mM sodium bicarbonate inmethanol/water (1:9), a flow rate of 1 mL/min, a sample volume of 20 μL,and a run time of 10 min).

The ratio of SBE_(6.6)-β-CD to activated carbon was about 8.4:1 to 8.5:1(about 8.44:1). Once washed, the reaction solution was passed (recycled)through the carbon for at least 2 hours to complete a first treatmentcycle.

A second column was charged with 32 kg (about 11-12% wt. of the startingamount of β-cyclodextrin) of SHIRASAGI® DC32 granular activated carbonand washed thoroughly with water until the wash samples had aconductivity level less than 10 μS (measured by ion chromatography(4.0×250 mm USP packing L50 or similar with mobile phases of 4 mM sodiumbicarbonate in methanol/water (1:9), a flow rate of 1 mL/min, a samplevolume of 20 μL, and a run time of 10 min)) as shown in the followingTable. Once washed, the reaction solution was passed through the carbonfor at least 2 hours to complete a second treatment cycle.

After the second treatment cycle, the SBE_(6.6)-β-CD was analyzed usinga Corona (ESA Bioscience) Charged Aerosol Detector to determine chlorideconcentration.

As shown in the Table, all of the samples had a chloride content of0.07% or less with 6 of the 9 samples having a chloride content of lessthan 0.05% (the limit of detection for the ion chromatograph). This isan improvement over measurements using the previous method shown in FIG.10 which had only a 65% success rate (44 out of 68 samples) in obtainingchloride levels of less than 0.10%. This is also a significantimprovement over the previous method for samples than had been passedthrough two activated carbon treatment cycles as shown in FIG. 10 whichhad only a 48% success rate (20 out of 42 samples) in obtaining chloridelevels of less than 0.1%.

Average Chloride Column 1 Column 2 conduc- SBE_(6.6)-β-CD Contentconductivity conductivity tivity Lot No. (w/w) (μs) (μs) (μs)17CX01.HQ00080 0.07 10.00 10.00 10.00 17CX01.HQ00081 0.06 9.90 6.10 8.0017CX01.HQ00082 <0.05 6.92 8.87 7.90 17CX01.HQ00083 <0.05 8.91 8.16 8.5417CX01.HQ00084 <0.05 9.35 8.68 9.02 17CX01.HQ00085 <0.05 8.53 8.95 8.7417CX01.HQ00086 <0.05 6.92 8.10 7.51 17CX01.HQ00087 <0.05 8.32 8.46 8.3917CX01.HQ00088 0.07 10.00 10.00 10.00

Example 21 Purification of Activated Carbon to a Constant ConductivityLevel

A column can be charged with 32 kg (about 11-12% wt. (11.8-12% wt.) ofthe starting amount of alkylated cyclodextrin) of SHIRASAGI® DC32granular activated carbon and washed thoroughly with water until thewash samples have a constant conductivity. Following the water washes,an alkylated cyclodextrin solution portion can be added to the housingand passed through the carbon for a determined time period beforediscarding. A further alkylated cyclodextrin solution can be added tothe housing and passed through the carbon for at least 2 hours tocomplete the first treatment cycle.

A second column can be charged with 32 kg (about 11-12% wt. (11.8-12%wt.) of the starting amount of alkylated cyclodextrin) of SHIRASAGI®DC32 granular activated carbon and washed thoroughly with water untilthe wash samples have a constant conductivity. Following the waterwashes, an alkylated cyclodextrin solution portion can be added to thehousing and passed through the carbon for a determined time periodbefore discarding. A further alkylated cyclodextrin solution can beadded to the housing and passed through the carbon for at least 2 hoursto complete the first treatment cycle.

CONCLUSION

These examples illustrate possible embodiments of the present invention.While various embodiments of the present invention have been describedabove, it should be understood that they have been presented by way ofexample only, and not limitation. It will be apparent to persons skilledin the relevant art that various changes in form and detail can be madetherein without departing from the spirit and scope of the invention.Thus, the breadth and scope of the present invention should not belimited by any of the above-described exemplary embodiments, but shouldbe defined only in accordance with the following claims and theirequivalents.

It is to be appreciated that the Detailed Description section, and notthe Summary and Abstract sections, is intended to be used to interpretthe claims. The Summary and Abstract sections can set forth one or more,but not all exemplary embodiments of the present invention ascontemplated by the inventor(s), and thus, are not intended to limit thepresent invention and the appended claims in any way.

All of the various aspects, embodiments, and options described hereincan be combined in any and all variations.

All documents cited herein, including journal articles or abstracts,published or corresponding U.S. or foreign patent applications, issuedor foreign patents, or any other documents, are each entirelyincorporated by reference herein, including all data, tables, figures,and text presented in the cited documents.

1. A process for preparing an alkylated cyclodextrin composition comprising an alkylated cyclodextrin, the process comprising: (a) mixing a cyclodextrin with an alkylating agent to form a reaction milieu comprising an alkylated cyclodextrin, one or more unwanted components, and one or more drug-degrading impurities; (b) conducting one or more separations to remove the one or more unwanted components from the reaction milieu to form a partially purified solution comprising the alkylated cyclodextrin and the one or more drug-degrading impurities, wherein the one or more separations are ultrafiltration, diafiltration, centrifugation, extraction, solvent precipitation, or dialysis; and (c) treating the partially purified solution with a phosphate-free activated carbon having a residual conductivity of 10 μS or less and producing the alkylated cyclodextrin.
 2. The process of claim 1, wherein the alkylated cyclodextrin composition further comprises less than 500 ppm of a phosphate.
 3. The process of claim 1, wherein the alkylated cyclodextrin composition further comprises less than 125 ppm of a phosphate.
 4. The process of claim 1, wherein the residual conductivity in (c) is 9 μS or less.
 5. The process of claim 1, wherein the residual conductivity in (c) is 8 μS or less.
 6. The process of claim 1, wherein the alkylated cyclodextrin composition further comprises less than 0.5% (w/w) of a chloride.
 7. The process of claim 1, wherein the alkylated cyclodextrin composition further comprises less than 0.1% (w/w) of a chloride.
 8. The process of claim 1, wherein the alkylated cyclodextrin composition further comprises less than 0.05% (w/w) of a chloride.
 9. The process of claim 1, wherein the alkylated cyclodextrin composition has an average degree of substitution of 2 to
 9. 10. The process of claim 1, wherein the alkylated cyclodextrin composition has an average degree of substitution of 4.5 to 7.5.
 11. The process of claim 1, wherein the alkylated cyclodextrin composition has an average degree of substitution of 6 to 7.5.
 12. The process of claim 1, wherein the alkylated cyclodextrin composition has an absorption of less than 1 A.U., as determined by UV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for an aqueous solution containing 300 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 13. The process of claim 1, wherein the alkylated cyclodextrin composition has an absorption of less than 0.5 A.U., as determined by UV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for an aqueous solution containing 300 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 14. The process of claim 12, wherein the absorption is due to a drug degrading agent.
 15. The process of claim 12, wherein the absorption is determined by UV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for an aqueous solution containing 500 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 16. The process of claim 1, wherein the alkylated cyclodextrin composition has an absorption of less than 1 A.U., as determined by UV/vis spectrophotometry at a wavelength of 320 nm to 350 nm for an aqueous solution containing 300 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 17. The process of claim 1, wherein the alkylated cyclodextrin composition has an absorption of less than 0.5 A.U., as determined by UV/vis spectrophotometry at a wavelength of 320 nm to 350 nm for an aqueous solution containing 300 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 18. The process of claim 16, wherein the absorption is due to a color forming agent.
 19. The process of claim 16, wherein the absorption is determined by UV/vis spectrophotometry at a wavelength of 320 nm to 350 nm for an aqueous solution containing 500 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 20. The process of claim 1, wherein the phosphate-free activated carbon is washed with a solvent until the eluted solvent has reached the residual conductivity in (c).
 21. The process of claim 1, wherein the phosphate-free activated carbon is washed with water until the eluted water has reached the residual conductivity in (c).
 22. The process of claim 1, wherein the alkylated cyclodextrin is a sulfoalkyl ether cyclodextrin of Formula (II):

wherein p is 4, 5, or 6, and R₁ is independently selected at each occurrence from —OH or —O—(C₂-C₆ alkylene)-SO₃ ⁻-T, wherein T is independently selected at each occurrence from pharmaceutically acceptable cations, provided that at least one R₁ is —OH and at least one R₁ is O—(C₂-C₆ alkylene)-SO₃ ⁻-T.
 23. The process of claim 22, wherein R₁ is independently selected at each occurrence from —OH or —O—(C₄ alkylene)-SO₃ ⁻-T, and -T is Na⁺ at each occurrence.
 24. The process of claim 1, further comprising combining the alkylated cyclodextrin composition with one or more excipients.
 25. The process of claim 1, further comprising combining the alkylated cyclodextrin composition with an active agent.
 26. A product prepared by the process of claim
 1. 27. An alkylated cyclodextrin composition, comprising: an alkylated cyclodextrin having an average degree of substitution of 2 to 9; less than 500 ppm of a phosphate; and less than 0.5% (w/w) of a chloride; wherein the alkylated cyclodextrin composition has an absorption of less than 1 A.U., as determined by UV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for an aqueous solution containing 300 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 28. The alkylated cyclodextrin composition of claim 27, wherein the alkylated cyclodextrin composition has an absorption of 0.5 A.U. or less as determined by UV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for an aqueous solution containing 300 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 29. The alkylated cyclodextrin composition of claim 27, wherein the alkylated cyclodextrin composition has an absorption of 0.2 A.U. or less as determined by UV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for an aqueous solution containing 300 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 30. The alkylated cyclodextrin composition of claim 27, wherein the absorption is due to a drug degrading agent.
 31. The alkylated cyclodextrin composition of claim 27, wherein the alkylated cyclodextrin composition has an absorption of 0.5 A.U. or less as determined by UV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for an aqueous solution containing 500 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 32. The alkylated cyclodextrin composition of claim 27, wherein the average degree of substitution is 6 to 7.5.
 33. The alkylated cyclodextrin composition of claim 27, wherein the alkylated cyclodextrin is a sulfoalkyl ether cyclodextrin of Formula (II):

wherein p is 4, 5, or 6, and R₁ is independently selected at each occurrence from —OH or —O—(C₂-C₆ alkylene)-SO₃ ⁻-T, wherein T is independently selected at each occurrence from pharmaceutically acceptable cations, provided that at least one R₁ is —OH and at least one R₁ is O—(C₂-C₆ alkylene)-SO₃ ⁻-T.
 34. The alkylated cyclodextrin composition of claim 33, wherein R₁ is independently selected at each occurrence from —OH or —O—(C₄ alkylene)-SO₃ ⁻-T, and -T is Na⁺ at each occurrence.
 35. The alkylated cyclodextrin composition of claim 27, wherein the alkylated cyclodextrin is a sulfobutyl ether cyclodextrin.
 36. An alkylated cyclodextrin composition, comprising: an alkylated cyclodextrin having an average degree of substitution of 2 to 9; less than 500 ppm of a phosphate; and less than 0.5% (w/w) of a chloride; wherein the alkylated cyclodextrin composition has an absorption of less than 1 A.U., as determined by UV/vis spectrophotometry at a wavelength of 320 nm to 350 nm for an aqueous solution containing 300 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 37. The alkylated cyclodextrin composition of claim 36, wherein the alkylated cyclodextrin composition has an absorption of 0.5 A.U. or less as determined by UV/vis spectrophotometry at a wavelength of 320 nm to 350 nm for an aqueous solution containing 300 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 38. The alkylated cyclodextrin composition of claim 36, wherein the alkylated cyclodextrin composition has an absorption of 0.2 A.U. or less as determined by UV/vis spectrophotometry at a wavelength of 245 nm to 270 nm for an aqueous solution containing 300 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length
 39. The alkylated cyclodextrin composition of claim 36, wherein the absorption is due to a color forming agent.
 40. The alkylated cyclodextrin composition of claim 36, wherein the alkylated cyclodextrin composition has an absorption of 0.5 A.U. or less as determined by UV/vis spectrophotometry at a wavelength of 320 nm to 350 nm for an aqueous solution containing 500 mg of the alkylated cyclodextrin composition per mL of solution in a cell having a 1 cm path length.
 41. The alkylated cyclodextrin composition of claim 36, wherein the average degree of substitution is 6 to 7.5.
 42. The alkylated cyclodextrin composition of claim 36, wherein the alkylated cyclodextrin is a sulfoalkyl ether cyclodextrin of Formula (II):

wherein p is 4, 5, or 6, and R₁ is independently selected at each occurrence from —OH or —O—(C₂-C₆ alkylene)-SO₃ ⁻-T, wherein T is independently selected at each occurrence from pharmaceutically acceptable cations, provided that at least one R₁ is —OH and at least one R₁ is O—(C₂-C₆ alkylene)-SO₃ ⁻-T.
 43. The alkylated cyclodextrin composition of claim 42, wherein R₁ is independently selected at each occurrence from —OH or —O—(C₄ alkylene)-SO₃ ⁻-T, and -T is Na⁺ at each occurrence.
 44. The alkylated cyclodextrin composition of claim 36, wherein the alkylated cyclodextrin is a sulfobutyl ether cyclodextrin.
 45. A pharmaceutical composition, comprising the alkylated cyclodextrin composition of claim 27 and an active pharmaceutical agent.
 46. The pharmaceutical composition of claim 45, wherein the active pharmaceutical agent is a chloride sensitive active agent selecting from the group consisting of bortezomib, disulfuram, epigallocatchin-3-gallate, salinosporamide A, and carfilzomib.
 47. The pharmaceutical composition of claim 46, wherein the chloride sensitive active agent is carfilzomib.
 48. The process of claim 25, wherein active agent is a chloride sensitive active agent selecting from the group consisting of bortezomib, disulfuram, epigallocatchin-3-gallate, salinosporamide A, and carfilzomib.
 49. The process of claim 48, wherein the chloride sensitive active agent is carfilzomib. 